BlvdBrawler
Superstar
eh, she could just be getting out of a relationship and isn't ready/scared for something serious.
or she could be too busy with a job to get caught up in a relationship but is still horny
or she could just wanna fuck with no strings attached like the average dude
plenty of chicks out there who aren't looking for a relationship

You telling me if dude was Reggie Bush, laying down pipe at a frentic pace, girl would have said, "I really just want to get to know you better?"
Bottom-line, she's keeping her options open for something better. There's any number of reasons why, I just outlined the 3 most likely scenarios.