Why would my boyfriend not tell a girl that he has a girlfriend?

[yourstruly]

Long story short. She asked him out.They've been chatting on Facebook and talking to each other at school, made vague plans to meet up, borrowed each other books etc... And today I found out that during the 6 months they have known each other, he has never mentioned having a girlfriend. She doesn't even know I exist.

What am I supposed to think of this? Is he gonna cheat?

[zuperkrypto]

Mentally, he already has. get rid of him.

[boo]

dump him!

[RyanRyRy]

Probably ask him.
He might think that she's just a friend and that she can't do anything to him.

[muttiniraq]

He might. It sounds like he is keeping his options open. He might just be seeking physical gratification from one of you. I would vote dump him.

[HI!]

That is kind of a bad sign. He might not want to tell her because he is scared that she won't want to talk to him if she knew OR he might be interested in her. I am not saying he is going to cheat but you might want to watch out for it. But do not go paranoid, because he will more than likely drop you in a heartbeat if you do and may go out with the other girl. Good Luck!!!