Is it right that Paul won't ask Meg to come to his house for Poker night only because she is a girl?

My co-worker Paul is having a bunch of the guys over from work for a Poker Night. He has pretty much invited all the guys we work with... key word being guys, because I work primarily with men, and am the "new" person at the office. When I inquired about Poker Night, I was told I was not going allowed to come because I was a "girl", and for no other reason than that...