Yeah, I guess I meant like... obligation in the sense of a reasonable expectation within an ideally healthy reciprocal relationship? IDK. I think it isn't a useless concept for those, but I'll admit the fuzzy definition (legal, moral, ethical, enforceable...) makes it tough. LW is reacting more likely to their own emotional sense of what the right thing to do would be, and 'obligation' is the wrong word for that for sure, you're right. But it's also probably not a good idea to continue as partners, let alone co-parents, with someone whose actions and perspectives are even somewhat horrifying to you.