I assume the very fact that he asked the girl to go out at all means that he doesn't find her totally replusive.
Most Helpful Girl
I actually believe that when men (or women, because I've done it too) ask someone out for drinks it is mainly because:
1. they don't know you well & they don't want to commit to spending a lot of time with you in case you two don't get along well. (i.e., boring, no spark, crazy, etc.)
2. meeting for drinks is kind of like a pre-date "interview"...do I want to date this person?
3. I don't want to spend money on this person yet, not until I know that I like them better.