At the beginning of the film, Woody Allen and Bette Midler fool around in bed in their underwear and spanks respectively. We maybe see a miniscule portion of Bette Midler's butt. However, the scene isn't graphic and it cuts away before any sex is had.
Bette Midler and Woody Allen begin kissing in a mall movie theatre and then proceed to fall on the floor out of our sight. We briefly hear some noises indicating that they are either having sex or at least fooling around.
Lots of sexual discussion and jokes primarily related to the main characters' infidelities (including 1 with a prostitute). The talk isn't very graphic or descriptive but much of the film's dialogue is devoted to it.