If women have the same level of desire for sex as men, why is it creepy if a guy wants to have sex with her? (tried to keep the title decent, but that's the gist of my query)

Say that scene from a beautiful mind where Mr. Nash gets slapped.

"In one example of communicative incompetence, Nash approaches a pretty young lady at a bar. He hasn't a clue how to start a conversation, so she has to prod him to buy her a drink. He then suggests (in "scientific" terms) that they should cut past the small talk and move quickly to intercourse (which he describes as an "exchange of bodily fluids"). She slaps him, calls him a name, and walks out. "

Shouldn't sex be easy if girls have as much libido as men? You like the look of a person, he is talented/has a good job, is polite, then what's the need for courting?