Der Kizer wrote...
So you go on one date with her and are pissed that she knows other guys? Like, maybe she just has friends dude. Seems like you just witnessed her hanging out with somebody she knows. If you really care so much just ask if she's seeing anybody else.
^This
Although, just yesterday one of my dad's customers/friends was talking to me about how girls turn guys into players due to just the situation you described. Her son was having girl troubles like you. It seems guys are more insecure than girls are (or at least more posessive), so when a girl strays to other guys, the male loses self esteem and may start playing around with other women as a result (or become a neet). Of course, I brushed off that notion of hers and told her that men and women's libidos are different, which is why guys play around with women more so than the other way around. At first I thought she was just biased because she raises three sons, but she told me her ex boyfriend had a troubled past with women and it took awhile for her to reasure him that she wouldn't betray him. It's funny cause I always had this predisposed idea that men would fuck anything that walked and could care less about comittment. I grew up around guys like that, so it wasn't just the media's influence that had me think that way. But what she explained to me made me rethink things a little, just a little.