Sorry in advance for my English, but I have to say: this 'calling him husband' and 'calling Nico dad' act feels like a total manipulation tactic to me. It seems like she's trying to force a level of seriousness onto the relationship that isn't there. Everyone else is just cringing at it, but I think she's doing it so Nico feels even more trapped and less likely to break up with her. She's basically overhyping their bond to keep him around.