Good story. Although, I kind of checked out when (SPOILERS) I found Amicus cheating with Neferu. Not because I was angry about it, but you must also build trust after forgiving. To me, Amicus was never up to the task and it felt like there was never enough dialogue between him and MC to justify their relationship being so close. In summation, my complaint is a "What do you even see in that guy?". His good qualities do not redeem his bad ones, maybe it's just a personal thing that I don't enjoy people who make rash decisions :/ . Overall, it reminded me of the old days of fanfiction that can be super dark and edgy, except with good writing. Also, Amicus never fucks MC as passionately as he does with Neferu, let's be honest here.
The reason why you like Amicus in the beginning is because you felt special and appreciated. This is more of a personal thing, but I see sex as extremely emotional. Meanwhile, it seems to be a common theme that the wolves see sex as purely instinctual. When you see Amicus with Neferu, if you were like me, yeah, you can forgive him (which I do) but I can't convince myself that it wasn't emotional because that would be going against my personal meaning of sex. It is clear that that's not Amicus's priority especially when he's trying to get a handy from you in the bedroom or a blow in the prison.
And honestly, being rough to me is a lot more passionate. If you're being rough with someone in bed I'd assume there would be a lot of trust, and the other person would probably turned on by the idea of you wanting them real bad. Although, I can completely understand if you see it in a different light :)