Why did he ignore me at the bar? Please answer?

There is this kid i have been casually hooking up with this past month and a half. Were not in a relationship- hes gorgous. We hooked up last friday.. and then last night (which was friday) i saw him standing outside the bar with his best friend , and when he saw me he quickly hid behind his friend!! Hes such a *** hole.. why would he do this!