Well... Was the girl that close to you, or was she just with you for a good time? Cause he might have been doing you a favor - making sure you guy rid of her. Has he said anything negative about her before the incident?

If not, then I would not introduce any more girlfriend to him. He needs to be as pushed out of my life as I can possibly shove him. But heck I could never forget my sister doing something like that to me. I wouldn't want her around anymore.

And, obviously DUMP THE GIRL!

Dudddddddddeeee, that's the fucking worst. Dump the slut, but he's your bro, so of course it's going to be awkward for a while, but try to talk it out with him. You know, sometimes impulses get the best of you, and I have three brothers, so I know how similar brothers can get, taste-wise. But.. yeah, try to talk with him, and try to forgive him. What he did was not by any means cool or right, but you guys are still family, and that's my advice to you.

No it wasn't Gut-Chan. And she was worse than dumped. She's basically forgotten because no one with aknowledge her around my school anymore. She's so pissed off right now....xDD She had it coming!