Brick asks Maggie to promise to keep her voice down. In return, she asks that he make his drink the last one until after Big Daddy's birthday party. Brick has forgotten Daddy's birthday. He refuses to pretend he remembered and sign the card to the present Maggie bought. When Maggie protests, Brick reminds her of the conditions of his living with her. Maggie declares that his conditions are impossible.
Suddenly Mae appears carrying a bow—Maggie's "Diana Trophy" from her intercollegiate archery days. Mae chastises her for leaving it out for her children to meddle with. Maggie retorts that she should teach her children to keep their hands off what does not belong to them. She mocks the brood for all having dog names. Mae exits.
Brick chides Maggie for being so catty. Maggie retorts that her envy and longing make her so. She can no longer bear their relationship; she feels all the time like a cat on a hot tin roof. Brick suggests that she jump off and take a lover. Maggie, however, wants only Brick. She implores him to get fat and ugly so she can stand it.
Maggie fiercely locks the door and draws the curtains. Brick warns her against making a fool of herself. Maggie grabs him by the shoulder. He breaks away and fends her off with a boudoir chair as if a lion tamer. Maggie erupts into hysterical laughter.
Big Mama is heard trying to get in; Brick hobbles to the bathroom and kicks the door shut. Mama enters with news from the Ochsner Clinic. The tests show that all Daddy has is a "spastic! SPASTIC!—colon." A phone is heard ringing, and Sookey brings it in saying that Miss Sally has called from Memphis. Mama and Maggie relate the results of Daddy's tests to the near-deaf relation.
Mama starts out of the room but stops at the door and asks silently if Brick has been drinking. Maggie plays dumb. Mama persists: Brick never touched liquor before his marriage. Something is not right: Maggie is childless, and Brick drinks. When a marriage goes on the rocks, the rocks are in the bed.