Mr.__ and Shug sleep together just about every night.
Shug asks if Celie cares that she and Albert sleep together. Celie doesn’t really care, but she doesn’t say that.
Celie asks if Shug loves Mr.__ and Shug says she has "passion"—not love—for him. She can’t really love him, it seems, because he’s weak and indecisive.
Celie asks if Shug likes sleeping with Mr.__ and Shug admits that she does. In fact, Shug says, "Don’t you?"
When Celie admits that she has never enjoyed sex, that it feels just like Mr.__ gets on top of her and goes to the bathroom on her, Shug says that Celie is a virgin.
Shug tells Celie that sex can feel really good. Then she gives Celie a mirror and tells her to look at her own vagina.
Shug guards the door while Celie checks herself out. Shug directs Celie to look at her "button" (clitoris) and her "titties" too.
Celie tells Shug she doesn’t mind if Shug and Mr.__ sleep together. But Celie does mind, not because she wants to sleep with Mr.__ herself, but, we suspect, because she wants to sleep with Shug herself.