So, lets start with setting the scene. This was about 2 months ago, when me and my friend group were playing d&d. We have me(m), my gf(f), person A(m), B(f), C(m) and D(m), and we all play d&d together. We usually host this at my house because I DM and 2 of our 6 ppl live there. Relationships: A&B are their significant other, C&D have known each other for a long time and my gf came later to the group relative to the others and me.

Our sessions usually are very roleplay-y, and we usually get our adrenaline high, depict what our characters do irl and very sometimes physical (nothing more than a little push or picking someone up from their chair).

Then to the moment: the party was fighting a (very buffed) mind flayer, and he flayed person C's character to attack my gf's character. None of us expected what was about to happen. So the attack hit and person C PULLED OUT A KNIFE, AND STABBED MY GF in the upper arm. We all just froze, starting shocked at him. He still was grinning (probably from the energetic mood), until he realized what he did. His face went completely white and he (futile) tried to laugh it off. When I sort of came back to senses, i just said (screamed/shouted) "GET THE F*CK OUT!" he slowely stood up, and I jumped up, grabbed my chair and screamed "YOU GET F*CKING 5 SECOND YOU RETARD F*CKING B*TCH" he ran. A little bit after, having cooled down a (very) little bit, the cut on my gf's arm was a tiny one. Looking back, I know it wasn't attempted to really hurt her, and I know based off his personality he wouldn't deliberately hurt anyone, but WHY TF DOES HE BRING A KNIFE TO D&D??

Up until now, I've blocked all contact with him and we haven't played d&d since. I've heard from the other people from the group that he's sincerely sorry, but I don't really feel safe with him. WHO BRINGS A F*CKING KNIFE to a d&d session where he knows it sometimes gets heated. Mainly person D is trying to convince me to give him a 2nd chance, A is "on my side", if there are sides in this. B is trying to stay neutral, but is also trying to convince me to continue with the sessions and my gf refuses to speak about it. I'm just (as you probably can read) baffled why he brought a knife, and refuse to talk to him. I do feel kind of feel bad for entirely ignoring him, but he hurt my trust BIG TIME with this. Should I've talked about it with him at the moment or later? AITAH?