Desperately in need of affection, the sex-starved kitten-turned-cat closes and locks their door and shuts the porch windows. She tries to stoke the fires of passion by advancing toward Brick - but he turns her down:

Brick: Now what did you do that for, Maggie?
Maggie: To give us a little privacy for a while.
Brick: Don't make a fool of yourself, Maggie.
Maggie: I don't mind makin' a fool of myself over you.
Brick: Well I mind. I feel embarrassed for you.
Maggie: Feel embarrassed! But I can't live on this way.
Brick: Now you agreed to accept that condition.
Maggie: I know I did, but I can't, I can't. (She fiercely hugs him.)
Brick: Let go, Maggie. (She doesn't respond and he pulls her away.) Now let go, Maggie.

He greets her advances with repugnance, escapes her arms and hobbles into the bathroom. When he slams the door shut, he inadvertently finds himself with his face buried in Maggie's perfumed nightgown hanging on the bathroom side of the door. Despite his verbal protests and brooding bitterness, he strokes and caresses the material, symbolically showing his desire and need for her beneath a dormant virility.

During Brick's seclusion in the bathroom, Maggie cannot admit to Big Mama why she doesn't seem to like children and why they have a childless marriage. Big Mama vilifies her, implying that there is something wrong between her and Brick. She implicates the young wife as the cause of her son's drinking and marital problems:

Big Mama: Oh shoot, Maggie, you just don't like children.
Maggie: Why that's not true! I adore them - well brought up.
Big Mama: Well why don't you have some then and bring them up well instead of all the time pickin' on Gooper's an' Mae's?
Maggie: ...Big Mama, what you said about havin' children, it's still kind of a secret but...
Big Mama: Oh shoot, Maggie, stop playing so dumb. I mean, is he still drinkin' this stuff much?
Maggie: Oh, well he may have had a little highball...
Big Mama: Don't laugh about it! Some single men stop drinking when they get married. Others start. Brick never touched liquor before he was...
Maggie: (crying out) THAT'S NOT FAIR.
Big Mama: Fair or not fair. I want to ask you a question, one question: 'Do ya make Brick happy?' Well?
Maggie: Why don't you ask me if he makes me happy?
Big Mama: Cause I know that ...
Maggie: It works both ways.
Big Mama: Somethin' ain't right. You're childless and our son drinks... (She pats the bed to emphasize her point) When a marriage goes on the rocks, the rocks are there, right there!
Maggie: (now alone in the room) That's not fair.

While under the pretense of examining Brick's ankle, Dr. Baugh (Larry Gates) (Brick's high school doctor) confides that Big Daddy is actually dying: "It's malignant and it's terminal. He hasn't a chance." The truth has deliberately been kept a secret from everyone except the two sons.

At the birthday dinner, Mae directs her aggravating, obnoxious children in a song to Big Daddy, and she brags proudly but cruelly about the offspring she is prodigiously producing who will benefit from the inheritance:

They're all Pollitts, I'm proud to say, every one of 'em. And I know that Big Daddy's just as proud as we are knowin' there's a whole dynasty of his flesh and blood waitin' to take over.

Everyone gives Big Daddy a sixty-fifth birthday toast to his long life.

Rudely insensitive to his father's birthday party, Brick begins packing. Realizing that her childlessness puts them at a disadvantage for the inheritance, Maggie again fights to preserve his relationship with Big Daddy:

Maggie: You've got no cause to dislike him.
Brick: Do I dislike him?
Maggie: Well, it's obvious to everybody, especially to him. What's he ever done to you? What? Why do you hate him so much? What's he ever done to you?
Brick: Nothin'.

And then Maggie is told the awful truth: "That's right. Big Daddy is gonna die." She is genuinely saddened. Brick recoils from the truth of his father's impending death - he has no interest in his father or the plantation. Maggie, who knew poverty as a child, fears age without money. Battle lines are drawn: Maggie against Gooper, Mae, their children, and Big Mama - with Brick refusing to get involved:

Maggie: Oh, poor Big Daddy. I'm fond of him. I'm genuinely fond of that old man. I really am, you know. Oh, when he finds out. I wouldn't want to be the one to tell him. That's why you want to go now.
Brick: Yeah, that's why I want to leave now. You gotta do this for me, Maggie, please.
Maggie: And leave the field to Gooper and that wife of his? No sir. Let's face facts, baby. You're a drinker, and that takes money.
Brick: I don't want his money.
Maggie: Are you ready to settle for ten cent beer? 'Cause that's just what Gooper will dole out to you when they freeze you out. They got a plan, baby. Oh you should have heard them layin' it on Big Daddy - a mile a minute. Big Mama's already on their side. You're a drinker and I'm childless. We got to beat that plan. We just got to. I-I been so disgustingly poor all my life. That's the truth, Brick.
Brick: Have you, Maggie?
Maggie: You-you don't know what it's like to have to suck up to people you can't stand just 'cause they have money. You don't know what it's like. Never havin' any clothes. That dress I married you in was a hand-me-down from a snotty rich cousin I hated. You can be young without money, but you can't be old without it. Where did I fail you? Where did I make my mistake? Make that your last drink until after the party, please honey!

Their dialogue reveals the mysterious source of their discontented marriage. Her honest recollection of what went wrong between them is somehow related to Brick's relationship with a best (homosexual?) friend Skipper whom he idolized. [Although not clarified in their dialogue, in the original play, Maggie seduced Skipper in a hotel room to distract him from his homosexual attraction to her husband. Now, the story has been modified to suggest that Skipper seduced Maggie.] Maggie adds that ignoring the subject will only make it fester and grow worse:

Maggie: I think I made my mistake when I tried to tell you about Skipper. That's where I made my fatal error.
Brick: Maggie...
Maggie: I never should have confessed...
Brick: Maggie, now you shut-up about Skipper. I mean it, you got to shut up about Skipper.
Maggie: The laws of silence won't work about that. Not about Skipper and us. It's like lockin' the door on the fire in hopes of forgettin' the house is burnin' - but not lookin' at a fire doesn't put it out. This time, I'm gonna finish. That night in a hotel room, Skipper and I...
Brick: I don't want to hear about it.
Maggie: Why won't you face the truth just once about Skipper? About me? About yourself?

Suggesting that she cheated on him with his now-deceased best friend, Brick has since refused to sleep with her. Infuriated by reminders of the truth [a homosexual relationship or "friendship" heavily disguised in the film], Brick turns to face her - he half lifts his crutch after she has brought up the forbidden subject:

Brick: Do you want me to hit you with this crutch?
Maggie: You're still blamin' me for Skipper's death.
Brick: (advancing) Now don't you know that I could kill you with this crutch?
Maggie: Good Lord, man, d'you think I'd care if you did?
Brick: Skipper and I had a friendship. Now why won't you let it alone?
Maggie: It's got to be told.
Brick: But I don't want to hear it.
Maggie: It's got to be told and you never let me tell it. I love you, and that's worth fightin' for. Not Skipper. Skipper was no good.
Brick: Maggie!
Maggie: Maybe I'm no good either - nobody's good. But Brick, Skipper IS DEAD! And I'M ALIVE!
Brick: Maggie!
Maggie: Maggie 'the Cat' is ALIVE! I'M ALIVE! Why are you afraid of the truth?
Brick: Truth! (He hurls his crutch at her, misses, and pitches forward to the floor.)

One of Mae's children named Dixie (Patty Ann Gerrity), wearing an Indian bonnet, bursts into the room without knocking and fires a loud cap pistol at both of them: "Bang Bang Bang." Maggie gasps that the little girl hasn't been taught to knock before opening a door: "Otherwise, people might think that you're, you're lacking in good breeding." When she asks her uncle why he was jumping hurdles, Brick provides an appropriate answer for her - and Maggie:

Brick: Because I used to jump them, and people like to do what they used to do after they've stopped being able to do it.
Maggie: That's right, and that's your answer. Now go away little girl. (Dixie fires her cap pistol at Maggie two more times.) Stop it! You little no-neck monster.
Dixie (precociously): You're just jealous 'cause you can't have babies!

After denigrating Maggie because she cannot have babies, Dixie cruelly sticks her tongue out at Maggie and sashays past her with her stomach stuck out.

Maggie: See? They and Gooper gloat over us being childless - even in front of their little no-neck monsters. Brick. I went to a doctor in Memphis, a gynecologist. He-he says there's no reason why we can't have a child whenever we want. Brick? Are you listening?
Brick: Yes, Maggie, I hear you. But how in hell on earth do you imagine you're gonna have a child by a man who cannot stand you?
Maggie: That, boy of mine, is a problem I'll just have to work out.

When the birthday party moves indoors, all the guests including Big Daddy and Big Mama proceed upstairs and join Brick and Maggie. Deacon Davis (Vaughn Taylor) makes unsubtle comments about expensive "memorial stained-glass windows," suggesting indiscreetly that Big Daddy make a gift provision in his will for the church. The hypocrisy of Big Daddy's forty-year marriage to Big Mama is revealed when he turns away from her "birthday kiss" and insists that she stop all her "yammerin'." Now that he has been given a healthy new lease on life, he bellows at Big Mama that he won't put up with any more lies or let her assume control of his estate:

I put up with a lot of bull around here because I thought I was dyin'. That's when you started takin' over. Your loud voice and your old busybody buttin' in here, there, and everywhere. Sashayin' around here, makin' a big noise like a boss. I'm the only boss around here. I built this place with no help from you. And I'll run this place 'til the day I die. Now is that plain to ya, Ida? Is that perfectly clear to ya? Now I ain't gonna die. There ain't nothin' wrong with me but a spastic colon! Made spastic, I reckon, by all the lies and liars I've had to put up with around here. And all the hypocrisy I've had to live with these forty years I've lived with you.

As she slowly walks from the room with the immense, blazing birthday cake in her arms, Big Mama sentimentally protests that she has always loved him:

In all these years, you never believed I loved you. And I did. I did so much. I did love you. I even loved your hate and your hardness.

Maggie kisses Brick on the mouth before leaving. He immediately wipes off his lips with the back of his hand. Big Daddy and Brick are left alone for the film's long confrontational scene between father and son. Brick compares Big Daddy's two daughter-in-laws to two conniving, clawing cats "squarin' off" on his estate land:

Brick: Well, they're a couple of cats. They're sittin' on the middle of a big piece of land, you know, twenty-eight thousand acres - that's a lot of land. And they're both squarin' off, each determined to knock off a bigger piece whenever you let go.
Big Daddy: Well, I got a surprise for them babies. I ain't gonna let go for a long time yet if that's what they're waitin' for.

After Mae attempts to eavesdrop ("spy"), Big Daddy criticizes Brick for his marital problems, their childlessness (after hearing reports from Big Mama (through Mae and Gooper) that Brick refuses to sleep with Maggie), and his drinking:

Big Daddy: They say Maggie sleeps on the bed and you sleep on the sofa. Is that true or not? If you don't like Maggie, get rid of her! What are you doin' over there now?
Brick: Fresh'nin' up my drink.
Big Daddy: Son, you know you got a real liquor problem?
Brick: Yes sir, I know.
Big Daddy: Is that why you quit your job, sports announcin', because of the liquor?
Brick: I guess so, yes sir, that's it.
Big Daddy: Don't guess about it, son, it's too important.

Big Daddy doesn't feel preoccupied with his own imminent mortality: "The sky is open again, boy, it's open." Reprieved from death, he desires "pleasure" with a "choice" woman to make up for his forty years of his distaste for Big Mama. And he persistently interrogates Brick about his alcoholism and why he has irresponsibly thrown his life away. Brick is only interested in drinking to find oblivion - a peaceful "click" in his head:

Brick: Somethin' hasn't happened yet.
Big Daddy: What's that?
Brick: A click in my head.
Big Daddy: Did you say, 'click'?
Brick: Yes sir, the click in my head that makes me feel peaceful.
Big Daddy: Boy, sometimes you worry me.
Brick: It's like a switch, clickin' off in my head. Turns the hot light off and the cool one on and all of a sudden, there's peace.
Big Daddy: Boy, you're, you're a real alcoholic!
Brick: That is the truth. Yes sir, I am an alcoholic, so if you'd just excuse me...
Big Daddy: (grabbing him) No, I won't excuse you.
Brick: Now I'm waitin' for that click and I don't get it. Listen, I'm all alone. I'm talkin' to no one where there's absolute quiet.
Big Daddy: You'll hear plenty of that in the grave soon enough. But right now, we're gonna sit down and talk this over.
Brick: This talk is like all the others. It gets nowhere, nowhere, and it's painful.

With fatherly love, Big Daddy forces Brick into a no-holds-barred discussion of his drinking and his total disregard for the family's fortunes. He interrogates him repeatedly and withholds his crutch from him:

Big Daddy: Now, why do ya drink?!
Brick: Give me my crutch.
Big Daddy: Tell me first.
Brick: No, you give me a drink first and I'll tell ya.
Big Daddy: Tell me first! First you gotta tell me!
Brick: All right, disgust!
Big Daddy: DISGUST WITH WHAT?
Brick: You strike a hard bargain.
Big Daddy: Boy, do you want liquor that bad?
Brick: Yes, sir. I want liquor that bad. (Big Daddy hands him his crutch)
Big Daddy: Now tell me, what are you disgusted with?
Brick: Mendacity. You know what that is. It's lies and liars.
Big Daddy: Who's been lyin' to ya? Maggie? Has your wife been lyin' to ya?
Brick: No. Not one lie, not one person. The whole thing.

After goading Brick and hearing that he drinks out of "disgust" - and further pressed, discovering as an after thought that he does so because of "mendacity," Big Daddy has had a lot of experience with mendacity. In his long marriage to Big Mama and with other things such as church, lodges, and clubs, he has out of necessity, adjusted and lived with lies and pretense:

Mendacity. What do you know about mendacity? I could write a book on it...Mendacity. Look at all the lies that I got to put up with. Pretenses. Hypocrisy. Pretendin' like I care for Big Mama, I haven't been able to stand that woman in forty years. Church! It bores me. But I go. And all those swindlin' lodges and social clubs and money-grabbin' auxiliaries. It's-it's got me on the number one sucker list. Boy, I've lived with mendacity. Now why can't you live with it? You've got to live with it. There's nothin' to live with but mendacity. Is there?