Been wanting to talk about this for a while lol but I get nervous about posting!
Anyways I love that Emmet was canonically Mary Jane’s favorite teacher (I think lol)! It makes me happy because I headcanon that it’s hard for Mary Jane to find her own joy in some things and prefers to be alone, especially in school and she feels like, even though she wasn’t bullied she can relate to him regarding feeling isolated (and not always in a negative way). And I also headcanon that, realizing that he’s making a difference for the kids, (especially the one that is known to not like many things) Emmet starts to feel a little better about not being able to teach at the universities that he wants.
I also think he’s pretty hard on himself and has a low self esteem as well as trauma from being bullied so seeing that he’s loved and he can be appreciated really helped him at that point in time.
I like to think that Emmet tries not to think about Mary Jane after the world ends because it hurts him too much to think that she may have had a horrific death or is struggling or being hurt back on earth.
I think that when Emmet went on to be an astrocitizen Mary Jane was upset but never told anyone. I think she felt abandoned because Emmet was one of the only people she could relate to and feel comfortable being vulnerable with. I think after the world ends, she feels conflicted. She doesn’t want to imagine that anything bad happened to Emnet but at the same time, she feels that she has to radically accept that everyone she loves will die terribly and “this is the way the world is now.” And maybe he deserves it for leaving her.
But yeah I like to think they had a mentor/mentee or father/daughter or sibling type of relationship!