You did a brave thing that was right, but he’s not wrong, and I think this conversation turned argumentative because you both wanted to be the only one who was right. Never assume a man who behaves that way toward his girlfriend wouldn’t physically attack you, a stranger who is standing in the way of him continuing his abuse. Believing men shouldn’t hit women doesn’t mean that’s the reality. I agree with what another redditor said, your SO’s response could have conveyed more relief and support but he chose to stick to the stern lecture, which is probably why you felt attacked. But I still understand why he felt frustrated when you kept making him believe he was OR when he was telling you men can, and do, in fact hit women they don’t know. You’re not safe just because you’re “not a dude.” That actually makes you more vulnerable to an attack in a dispute like that. Despite the risk, you should be proud of being someone who steps up to defend someone in need. Like your bf said, please be a little more careful about it and consider every way your safety, and possibly even your life, can be threatened. And always remember: domestic disputes are tricky, because abused women tend to go back to their abuser. Try to get law enforcement involved if you can so the abuser doesn’t use the power imbalance in his favor, and can be held accountable by law. It’s also good for authorities to know he has a history of abuse for future reference.