Definitely an interesting start. I love genre subversion stories so that is an instant + for me.
I doubt it's the case but considering he keeps mentioning Simon, I can't help but wish he was actually a gay man just to throw all the nobles harem preparations in the trash lol.
Some day it will happen!
Something I'm actually looking forwards to is if his physics background comes into play. Considering it was mentioned and that feels like a very specific thing to mention and definetly offers implications about his intelligence It could be a cool angle. I always appreciate when stories dive into mixing science and magic.
Oh and I absolutely think Mary's story is true but that she is a rare case. Considering we know that there are slave work camps I don't believe for a second that the kingdom is actually just in having slavery. (Not that there is a just way to have slavery) But I did appreciate the MC's instant "nope" out of there even if he let them talk him around to it. I hope he still rejects her anyways until something happens that forces the change rather than him just giving into the system of slavery.