Back up.

Harry Burns: You realize of course that we could never be friends.
Sally Albright: Why not?
Harry Burns: What I'm saying is - and this is not a come-on in any way, shape or form - is that men and women can't be friends because the sex part always gets in the way.
Sally Albright: That's not true. I have a number of men friends and there is no sex involved.
Harry Burns: No you don't.
Sally Albright: Yes I do.
Harry Burns: No you don't.
Sally Albright: Yes I do.
Harry Burns: You only think you do.
Sally Albright: You say I'm having sex with these men without my knowledge?
Harry Burns: No, what I'm saying is they all WANT to have sex with you.
Sally Albright: They do not.
Harry Burns: Do too.
Sally Albright: They do not.
Harry Burns: Do too.
Sally Albright: How do you know?
Harry Burns: Because no man can be friends with a woman that he finds attractive. He always wants to have sex with her.
Sally Albright: So, you're saying that a man can be friends with a woman he finds unattractive?
Harry Burns: No. You pretty much want to nail 'em too.
Sally Albright: What if THEY don't want to have sex with YOU?
Harry Burns: Doesn't matter because the sex thing is already out there so the friendship is ultimately doomed and that is the end of the story.