I get the feeling this is going to continue being a source of tension until it gets to the point where he either has to start being more open with her or lose her. It would be some nice character development for a MC severely lacking in it at least.
The game has been remarkably free of conflict unless the player invites it. I don't mean there hasn't been
any — certainly there's been a fair bit with Mary's parents, both between them and with regard to the MC and Mary's relationship — but with pretty much anything else the player has had to make the "wrong" decision to initiate it.
This would, indeed, be an interesting source of future conflict and growth. The MC has changed Mary. Can Mary change the MC? In a relationship crisis, can he change for her? Again, I have absolutely no way of knowing if that's how the game is going to go, but it would be fertile narrative territory.
Having thought a lot about the future possibilities (and still stopping every few minutes to do Numfar's "yes he's on the spectrum" Dance of Joy...a reference that will only make sense to
Angel fans) I'm starting to think that while I'd
prefer to see the MC and Mary make a go of it, I think I'd respect the story logic more if they couldn't. I won't
disrespect the story if they survive and flourish, but pretty much everyone but Simone is telling the MC that he and Mary are doomed.
Now, it's true that Simone understands Mary better than anyone else in the game (including the MC), but Simone and Mary are also playing a slightly dangerous game in which Simone has a lot of emotional and sexual control over Mary, and it's not clear that the MC is always a consideration in the M/S relationship.
Again, all purely speculative and very possibly misguided. But intriguing.