Is it sexual assault if I do that to my girlfriend of 5 years?
In many contexts it would be sexual assault, but in many it wouldn't be. I think you're just assuming it's sexual assault because you don't like the idea of a book that teaches people how to "pick up women"
FYI, the context behind that sentence is:
> offering advice on what to do AFTER a man has met a cute girl, gotten her phone number, gone on dates, spent time getting to know her, and now are alone behind closed doors fooling around