I have an older sister. We didn't grow up together, in fact, we met for the first time about a year and a half ago. We have a lot in common and became good friends.
I dislike her boyfriend, who she has been with for about 5 years. She has a very love/hate relationship with him. She's always saying that he's an asshole, cheat, alcoholic, druggie and that she dreams of leaving him but cant, and she is open about the way he treats her and how she has tried to get rid of him but they always get back together.
She will sometimes mention casually things like "oh, I used to have _______ but Boyfriend smashed it during an argument" or that she's gotten used to him putting her down and gaslighting her, it doesn't bother her anymore and she is now aware that she's not crazy like he made her think.
Ive only met him twice, both at family events where lots of people were there. Only spoke to him one of those times, and he made a joke about killing her beloved dog, but I don't think anyone else heard it. Something about it was just "off".
Ive told her many times that she could do better than him and that she deserves someone who is nice to her. She knows, and is aware its not right that he treats her badly, but says she cant leave him as he wouldn't manage without her. he spends all his own money on alcohol and drugs and its her house and he has nowhere else to go.
I know that he's definitely emotionally abusive, but Ive never suspected it was physical, until now. She was scrolling through the pictures on her phone, showing me photos of something cute her dog did. She flipped through a series of pictures of her dog, then went too far and the next picture that came on screen was a selfie, where she looked upset and had a bloody nose. She quickly flipped back to dog pictures and was like "oh, just ignore that". I noticed a few photos as she scrolled through looking for a photo she took ages ago that were selfies, but ones where she did not look her best and looked unhappy, but no others where she appeared to be bleeding or anything.
We didn't talk about it, although I wanted to ask. I suspect he did it. I don't know what to do.