both slobber quite a bit, and both require attention 24/7. instead of getting a dog, why not convince him he should have a baby? a baby won’t steal his socks (probably) or leave fur all over the house (although they do create other types of mess). but hey, a baby will eventually learn to speak and communicate with you, and that is something a dog can never do.
if he is imagining you carrying a baby, rocking her to sleep, as well as feeding and taking care of her, and just being a great mum overall, he must have imagined himself holding the little bundle in his arms, too. why not 