Confronted the Alpha in the group of family friends for getting touchy with my sister.

He’s 25 and is the leader of the group of 10 of us. I’m 19 and for the past couple years I’ve seen him do things with my sister I find uncomfortable. Most notable is one time we were all sitting down on the couch and he was acting playful with my sister, he ended up putting his hand on her thigh while I was sitting next to her. I was too beta to call him out on it.

There’s also another girl in the group a 16yo. With her he’s extremely flirty. They act like a couple, but they don’t act too sexual in front of everyone. It’s a group of family friends, we’ve all talked about how weird it is. What’s even weirder is his brother likes her too and frequently calls her at night, it shows he gets jealous when his brother (Alpha) is at gatherings instead of work, 16yo prefers older brother.

In the past I confronted my sister about it saying don’t play along when he hugs her from behind, but she still does, when I confront her It looks like she knows what’s happening and doesn’t do it the next time. She does it again today.

We went to a haunted house and he likes to tickle her back and asked to take a picture of just him and her. I don’t know if I acted out of weakness or if I’m enforcing boundaries, but when we got to the house I pulled him aside and told him to fuck off with my sister, and how she isn’t the other girl in the group. He laughed in my face, then I repeated myself. He laughed again and I shoved him telling him seriously to fuck off. Ended up saying bye to everyone while he stayed in the room staring on his phone. Didn’t tell anyone.

What’s going through my head is that my sister actually has attraction for him and I’m not with that. I don’t like when friends are involved with family similar to scar face situation if you’ve seen that movie.

Also I feel as though I needed to push myself so I don’t view myself as a beta. This is the first time I’ve really stood up for myself.

I don’t know what to do with my sister. I’m thinking it may still happen just behind my back, I’m mate guarding my sister as I can what his game is from afar. I don’t have a problem with my sister dating, just not with mutuals.

I’m thinking confronting her about it in the past may have been bad because she always gets emotional about it, denying everything. Then eventually agrees that it’s messed up. He’s taller than me and has a good job and wife, desirable by other woman. Hypergamy is why I believe she’s attracted. Should I even be putting up with this?