About my girlfriend cheating?

[Terry]

we stop talk talking for 9months. she admits to talk another guy but it was just talk. she claims he doesnt live around here, and that she never saw him face to face. he was on here facebook page, and the first time I asked her about him lied that she dnt talk to nobody. then after she was caught she told me she was gonna stop, but she didnt. she also called his # by heart, I think she sleep with him or someone else. she always claim to be tired from school, so we barely have sex

[Z]

Leave her.

[nadia]

She's def hiding something...I say u dump her cuz she's cheating on u

[Maverick]

I'd say, leave her now, while you are still young and can find someone else. She may apologize, but she'll do it again.
"Cheating" is common when a relationship has continued for a long time. not when you are both young.
Sooner or later, ALL men "cheat". It is how we are wired. That some women don't understand this is clear.
Hogamus higamus, men are ploygamous.
Higamus hogamus, women monogamous"
(William James Psychologist and Philosopher.)
The bit about women is no longer true, by the way.
Yes, it hurts, but think about the reality and come to terms with life.