Beetlejuice mpreg idea
Alright, so like here me out. Yes, I could be all like he's a demon so that's how this all works, but like what if Juno curses Beetlejuice to get pregnant and have a child. Like, she hates him. This is canon. So, like think about her deciding that the perfect way to punish him is for him to have a "disappointing kid" of his own. So, either she just poof makes it happen, or designs the curse to take full affect the next time he does the do (like with some random guy or ... maybe some super sexy boring ghosts).
Just like imagine ya'll. Like poor bug boy would be absolutely terrified. Not of the situation, but just because he has no idea how to raise a child and is terrified of messing up. But then like Lydia would remind him it's going to be okay, and how she's so pumped to be the best aunt ever! Barbara and Adam would share all their knowledge from all the books they've read to him, and you know do whatever they can to be there for him and comfort him and so on. Delia would be super excited and do her best to make sure he stays healthy. Charles doesn't really need the details, but he's happy to help where he can.
Just like tons of angst and comforty family goodness.