Was she overreacting or am I too relaxed?

Okay, so last night I had some friends over for a New Years party including my boyfriend, our mutual friend Jake, and his girlfriend Kim (my boyfriend had not yet met her previously)

She was pretty quiet all night but she always is when we see her, she only really talks to a couple of people because I think she's a bit awkward around mine and her boyfriend's friends, but she's always very pleasant whenever I've spoken to her, really sweet.

At the end of the night it was just the 4 of us and another of my friends. My boyfriend and Jake started wrestling on my bed, play fighting basically as teenage boys do. I was a little intoxicated but I thought it was cute and I was laughing whilst I was watching them thinking it was all just fun and games (which it was, I mean neither of them were in pain)

But then suddenly Kim just explodes, grabs holds of my boyfriend and yanks him off hers yelling at him to cut it out, she then proceeds to have an argument with my boyfriend about him 'showing off his muscles' and 'proving he's a man' and all this, when all it was was a little play fighting...I mean she went really insane I'd never seen her like that before, really really furious and I couldn't see why

Jake looked really embarrassed and kept awkwardly saying that he wasn't hurt or anything, I was chatting to my mate in the corner trying to avoid the conflict (which I feel kind of bad about that I didn't stick up for my boyfriend, not that he needed it mind but still) and then Kim gets up, I think she was crying, storms out without saying goodbye then Jake left awkwardly after

I think she was seriously overreacting to the whole thing, I mean it was just play fighting! Boys do it all the time, and to blow her top off like that to a guy she'd only just met, my boyfriend and in my bloody house was a bit rude. I mean my boyfriend's quite buff so maybe she was worried he would really hurt Jake but I know he wouldn't have, and anyway they were both laughing whilst they were fighting so what's her problem?

My mate reckons that to keep the peace I should go to her and apologise for my boyfriend's behaviour but I don't think I can because I think she was way out of line (which is a phrase she used to describe what had happened) and I don't know what I'll say to her the next time I'll see her.