Wow, I totally did not see that coming! Looking back, though, there were a lot of hints that Ann's husband was still alive.

Early on, I wondered if Baby was just pretending to be disabled. But then this ended up not being the case, as it was revealed he was being abused by his family. Near the end, before Ann and her mother-in-law were revealed to be the killers, I was hoping that Baby had been rehabilitated and was killing off his family (it would've been nice to see him get revenge!).

It's actually very sad and disturbing that Ann was never planning on helping Baby and just wanted him to be a playmate for her husband.