There is this girl who lives in my dorm and comes to visit my flatmate. She sits in our kitchen and talks with him and eats food he cooks. When we initially met, we seemed to get along and had pretty good banter. Then for some reason things changed and she always talks shit to me and it pisses me off, but I try not to show it and instead smile and try my best to A&A.

She keeps telling everyone this story about how I looked awkward when I tried to join a game of mafia that was already in progress then left because 'I wasn't getting attention'.

Today, my other flatmate was in the kitchen and he told me he was impressed by the weight I used that he saw on my Instagram story. The girl piped up that she knows a guy who apparently benches 3x his bw (saw his insta, i'm bigger than he is, wtf?) who would always post gym things and thus she's not impressed. I'm like, "ok". Also, she called me socially awkward and said I play it off well around other people, to which I replied "on a scale of 1-awkward, I'm 100" with a wide grin, because I couldn't think of anything else to say.

I challenged her to a fun arm wrestle over something she said and I beat her (obviously) but she put her hand to prevent it from touching the table saying that she somehow "won". We ended up having a small wrestle, where we held hands as if I was trying to get her to touch the table (I wasn't really trying, if I was it would have been easy to overpower her - I was afraid to hurt her) and commented that "we are holding hands, it must be love".

She then tried to complement my flatmate on his ring and accidentally said my name, to which I replied "Thanks" and purposely misinterpreted her compliment.

I described these situations, so maybe someone can tell me how I can 'win'/shut this girl down? Also, can someone explain why she is being annoying?

I've never experienced this before.