Even though Sonny keeps saying that he agreed to joint custody because of the custody battle and what it will do to his family, I think the main reason is because of his heart condition. Ava's money troubles don't change that fact. The fact that K was able to talk him into reneging that quickly is just pathetic. I agree about the dangers Avery will face because of Sonny. ICAM about Kristina, she is just insufferable. The only thing I disagree about is that AVa should withhold the meds.
I don't think he had any intention of reneging on the custody. That isn't how that conversation with Kristina went imo. But then Ava showed up whining about her money problems and asking for money and he tried to take advantage of that. Not sure what she expected, asking him for money. It's ridiculous. And yes, Avery isn't exactly safe with Sonny, but Ava made the choice to sleep with Sonny and had his child, knowing the dangers more than anyone. She did it anyway.