Concerned about scene with QUILTBAG Character

a) There's nothing inherently wrong about a book depicting a person who slams the door on a relative because the relative has come out as trans or bi or intersex or whatever. There are such people; there are such behaviors. It may not make your character an admirable MC but it doesn't make the book a repellent book.

b) If the plot trajectory of the book reads like "MC and mom are close; mom comes out; MC disowns mom", that's one situation; if the plot trajectory is more akin to "MC and mom were once close; mom is out of closet, MC knows about it; then series of events happen; MC becomes distant from mom", that's a very different situation.

If he knows of her identity/orientation AND THEN the "series of events" happens, it's mostly not going to be an issue anywhichaways. If he finds out about it in the same general timeframe as the "series of events", it could indeed come across as if MC is distancing from her because of that.


c) You've made it clear here in your post that the reason for the detachment from the mom is something other than her sexual / orientation identity. Any reason it can't be similarly clear in the ms?

Being LGBTQ doesn't make someone perfect, or obligate their friends and family to maintain ties with them if they otherwise wouldn't. Unless you tie the MC's poor relationship to his mother to her identity, I don't think a lot of people will make a connection.