Am I the asshole

My sister‘s boyfriend is verbally physically and emotionally abusive towards her, and everyone in my family just chooses to turn a blind eye because she chooses to stay with him. So am I the asshole for not wanting to spend time as a family with them because he’s a fucking piece of shit. I refuse to sit around and ignore the fact that he beats her ass every chance he gets, I support her and I want her to leave him but I will not sit around and have a family barbecue and eat food with him like he’s a good man. Not only is he not a good man to her he’s also a piece of shit father. All opinions are welcome