There is a guy I work with who seems to be interested in me. He flirts with me all the time and we've hung out quite a bit outside of work. Sometimes when we are alone or he if there is other guys with us, sometimes he talks about other girls. Whether they have hit on him or he's hit on them or he thought they were hot, etc. Most of the time I give him an eye roll and walk away. Why do guys do this? He definitely seems to be interested in me, but this makes me second guess it. Any comments?