If a guy really likes you then he will still likely want sex...but the difference is that he will wait patiently. He will still date you, wait patiently and not try to get it from somewhere else. It's hard to find guys like that...even harder to make yourself wait when you think you're ready for it with someone.
I've fallen for it a few rounds myself. It's something majority of girls will do multiple times before actually learning anything from their mistakes. Look back on those guys and guys that you know are only after that. Are there some common personality characteristics there? The answer is yes.
Guys who only want sex (and are getting it) are generally more cocky and loud than guys who are in it for more than just that. They are the loud ones who go around whistling at every @ss they see go past. They are the ones who you see around corners and behind buildings trying to flirt their way into someone's pants. Some are more subtle though...they'll get to know you, try to get some and when you say no, they'll throw the equivalent of a fit and threaten to leave you and stuff.
Bottom line: if the guy is pushing you even when you've said no more than once...drop him. No means no and he needs to learn that. quote_girl