My Friend Has a girlfriend and his girlfriend is my girlfriends sister. And He and this other girl were so called flirting. My girlfriend told me this and His Girlfriend was crying and I was telling that other girl if they were flirting and it turned into this big fight. And I didn't join and say stuff to that girl it was just my girlfriend and that other girl.And It just ended.. But my girlfriend is SUPER pissed and she told me to Stfu (Shut The Up) And I think that if I text her she'll dump me I don't know what to do. Text her and talk about it or Just give it time?

Did you tell her what was going on? I don't understand what went on. Leave it alone and let her cool off I guess