It's a pretext, sure. That's the point.

I think there's a deeper point: human interactions are multilayered and the surface layer does not necessarily carry the most important meaning. The meaning can be -- and often is -- masked by something else which should not be interpreted literally.

"It's a false pretext" is not even wrong -- it's just not a correct way to think about the situation. A "pretext" is a way to express in a socially acceptable fashion a deliberately ambiguous meaning which, if said explicitly aloud, would change the dynamics of the situation completely.

Human interaction, especially of a sexual nature, just is not reducible to the straightforward exchange of "wanna fuck?" information bits.