if you are going with the attitude "I am going to spend effort and money on you, you better give something back", then you better go to the hooker. Saves you time and uncertainty.

first of all, if you want to really understand guys, stop thinking we will behave like women. In most cases, women will have to love or at least like a guy to have sex with him. In most cases, guys are on the opposite side - we can "have fun" without attaching some feelings to the whole thing. It really is just a fun, no strings attached. Don't expect us to start behaving as if we came from a Jane Austen book. But more often than not, physical intimacy will lead to awakening feelings and greater emotional impact. Don't assume that every guy that "wants to have fun" is a womanizing son of a *****. He just wants the opportunity to get to know you without having to plan the wedding after a week. It's just the way it is. Men and women are wired differently concerning just about everything, so why would this area be an exception? Give them the benefit of the doubt, maybe some guy surprises you :)