It's always difficult being the friend of someone in an emotionally abusive relationship. You never want to comment on someone else's relationship, especially if that person is the type to cut off all contact with you for doing so. When I asked people about if they would talk to their friend in the relationship about it, many of them responded that they'd mention it in passing, but if nothing happens, they they'd just let it go. Although I wish I could say that I have a better alternative, I don't. You can't force your views on someone else, no matter how frustrating it is to watch.
However, I will say that to those people who are in fucked-up relationships, you don't get brownie points for staying. Many people my age have heard it all before. “You guys aren't right/made for each other.” “Why settle down so soon?” “Why don't just go explore this, this or this?” Our first instinct is to try to prove them wrong by staying. No matter how painful/hurtful the relationship is, we stick it out just to spite the naysayers. We push others away so we don't have to hear their voices every damn time. We think that the experience will end up making us stronger in the long run. No. Don't force what is not there. There is no magical morality prize at the end of the road. It's just a train wreck waiting to happen.
I'm not writing this to steer anyone away from their significant others, but I just want everyone to be cautious when the signs are all there. You can try to ignore pain. You can turn your head, but, like a scary movie, you have to turn back to the screen at some point.
Be selfish for once. You can be their wife/husband/”soul mate,” but if all signs point to you being unhappy or hurt by this person who is supposed to love, protect, and cherish you, walk away. It is not defeat if it simply is not working.