In Closer, sex and power go hand-in-hand. Throughout the play, relationships are shown to be something more akin to power struggles than loving commitments, and sex is used to gain power in these relationships.

Sex is used to exert control over people's lives in many instances. For example, after Anna leaves Larry for Dan, Larry refuses to sign the divorce papers unless Anna has sex with him. He does this not simply because he wants to have sex with Anna one last time, but because he knows that by doing so, he'll create a rift in Anna and Dan's relationship—which he does. Dan is unable to forgive Anna for sleeping with Larry again, so Anna eventually goes back to Larry feeling guilty, which gives Larry the power in the relationship, just as he wanted. So, sex is used in this very calculated way, especially by Larry, to make others feel jealous and guilty, giving him the upper hand.

How does each character exert power? Larry is cold and consciously seedy about the way he uses sex to pit people against each other. The way he tells Dan about his night with Alice is especially ruthless.

Dan exerts power in the same way a child might. He lashes out when he doesn't get what he wants and eventually becomes violent. He seems to need sex to feel good about himself. It's a pride thing to him. With Larry, sex is a means to an end; with Dan, sex is the end. He lies and whines to get what he wants.

Anna is probably the least powerful character. She is relatively easily swayed by both Larry and Dan. Anna doesn't really know what she wants. She is dissatisfied with Larry, then let down by Dan. Her power comes from allowing herself to be the object of both men's desires, but she ultimately is not deviant or cunning enough to use it to get what she wants.

Alice is an interesting character. She is pushed around and used by Dan and seems to be emotionally dependent on him. She has no power over him whatsoever. But as a stripper, she completely dominates Larry, bringing him to tears in a strip club. She uses her sexuality to take his money. The other interesting thing about Alice is that she never tells Dan her real name. It's one piece of herself that she keeps hidden from him, which is a power move that most likely leads Dan to wonder if he ever truly knew her.

Larry seems to be the most successful with his use of power. He gets the woman he wanted for a time and is able to move on when it ends, and he destroys both of Dan's relationships just for the fun of it. Anna seems to be the least successful, seeing as how she is rejected by the man she thinks she wants and ends up alone.