This isnt all that weird if she wants to have kids with him. Wanting to be his mom is weird. Usually he wants his mom and she wants her dad. Or someone defined in relation to their parents.
The only affection people experience for a while is through familial relations so I feel like young people (as in the pic) just use these terms as short hand while learning about things. I think explicit incest fetish is a leap of an assumption.
Ma'am I know your bf is probably (statistically, even) a manchild who'd throw a fit if asked to do chores, and I'm glad you're happy but I dunno if you should be supporting what could be malicious incompetence ✨
he was right about a lot of things, and the things he was wrong about still led to interesting insights that were right. people just hate him because the subject matter is frequently uncomfortable (and also the man himself was, like nearly every theorist of the 19th century, a complete freak)
Honestly I'm so jokerifed and deep in ironic nihilism at this point that I think unresolved Oedipus complexes could probably explain the majority of weird behaviour in society.
I'm so glad I'm past that age where being a pathetic manchild is in any way acceptable. It makes dating so much easier when I pretty much always pass the first date sniff test.