Robert and Nina are seen changing their clothes. Nina takes off her blouse and shows her top slip; she continues to undress and peeks around the door, wearing top and bottom slip. He is seen bare chested.
Charlie is a womanizer.
Robert and Janis briefly make out. There is an interrupted seduction scene without any nudity.
Much of the film has to do with sex, but "sex" is never actually mentioned. Divorced man reads a steamy romance novel. A divorced man out on his first date with a young woman is surprised to realize she is very sexually experienced, even with his roommate.