Hey r/seduction, I have a big problem on my hands right now. My GF and I of 4 years ended up going to the same college. It's only the 1st week so we haven't made a ton of friends, but we regularly hang out with the same group of thesr 5 guys and ourselves. In an effort to help my roomate get laid before school started, I came to r/seduction looking for advice (So I could be a good wingman) and realized that one of these 5 guys who we will call T is trying to game/steal her. I'll give you some examples: When we first came here he told her that if "she ever had any problems she could go to him". When were out he will never look at me or acknowledge me. When we both walk in our mutual friends dorm rooms he will say her name in a joking manner and then try to start a conversation with her immediately and ignore me, if I say anything he will attempt to cut me off. He constantly touches me in public(Shoulder, etc) , asks me to do shit for him (Hold drink, pitch in 5$ for a $10 pizza I ate one slice of, etc. I don't actually do any of that bs, but he's still trying to AMOG me). He always try to physically put himself between us. Today while we were all smoking he pulled the, "Just because there's a goalie doesn't mean you can't score" joke and everyone laughed, including my GF (It was a little awkward). He then turned to her and said "But don't worry about it guy, because we wouldn't do that to you, she's part of the crew" While smiling. My immediate response was "I'm glad to hear that, because if you tried to pull that I would have to kill you in your sleep with a broken spoon" (It didn't come off as creepy or threatening, everyone laughed a lot louder than the when he said his joke.) I've been using some of the advice I found here such as ignore/accept and amplify, being nice to him to make him seem like a bigger dick/etc. But nothing seems to be working.

Some of the other guys have already warned me about T, and they know what's going on. Considering my GF just thinks he's being a nice guy at this point, I don't think confronting him or trying to explain Game to my GF would be a good idea. T would never even have a chance of getting with my GF because he is extremely unattractive (overweight) and seems to be pretty deep in the friendzone , but he is ruining all of our social gatherings for me and is even starting to piss some of the other guys off. What can I do to shut this shameless wannabe AMOG down?

TLDR: Guy tries to amog me with textbook bs, it's obvious, how can I keep shut him down while keeping all our mutual friends.