mainbutter: Yes. A few times. If they can't respect their SO, which is supposed to mean so much to them, then how good a friend are they really? Do I want to be associated with someone who cares so little about how their actions affect other people?

Not worth it. You burn more bridges than just with your SO if you make a choice like that. I'd treat anyone who abused or neglected their dog in a similar way too. Don't want someone like that around me.