OP, I am so sorry that you were abused as a child. Sadly, I had presumed this would be the case since your first few comments. The mindset of an abused child who tries to keep it quiet, or minimise the truth to keep her parents happy, is exactly the one you have used as an adult to cope with, and deny the reality to yourself of what you have clearly described as a sexually coercive relationship with your OH.
The language you use about past experiences with him is very telling, not to mention upsetting. You keep describing him pressurising you to do certain things, and then you acquiescing, despite not enjoying the things you have done. This is sexual abuse. You use the classic abuse victim's self-denial tool - because your background of childhood abuse has (wrongly!) taught you that you don't really have proper rights in what happens to you sexually, and because your OH keeps putting on the pressure, you mentally and verbally reframe this sexual abuse, as you having some power and say in the matter - saying you did it to please him, or you didn't mind. Just as you coped as a child by telling yourself you were protecting your parents, you are deluding yourself that because you have not been forced kicking and screaming into acts with your OH, then things have been 100% consensual.
Most men, whose OHs have been abused as children, or raped, etc., err on the side of being cautious when it comes to sex with those partners. No matter what their own sex drive, or personal turn-ons, they always want to make sure that their partner is comfortable with what's happening, that it is fully consensual, that they are not doing anything that upsets them in any way.
Your Oh, on the other hand, knows you were sexually abused as a child, and pressurises you into sex acts that you don't really want to do, and which he knows you will eventually give in to if he presses. And they seem to be demeaning, depersonalising acts - sex toys, filming you, etc. (I have no personal issue with sex toys, I just know that some victims dislike them because of the derealisation that some suffer during abuse).
I have said before, and will repeat it, that I strongly believe that if you were to describe the minutiae of your whole relationship with him, then we, or more appropriately, a therapist, would be able to clearly see that he subtly abusive in other ways. You are probably in denial that he is sexually abusive outaide of this horrific betrayal, because of your assertions that he is nice and normal otherwise. However, I bet the person who abused you as a child appeared normal, even nice, didn't he? (Am presuming it was a man) Please think about that.
You say you don't think he was trying to hurt you - you are most like correct because he didn't think about you enough to even consider your feeling at all. He has used you like a commodity, like an item, like he is a pimp sharing his prostitute with whomever it benefits him to. Your feelings in this matter didn't even occur to him. This is a man who cannot understand that women are real, full human beings.
A man like this must have sickening beliefs about women. I would not have a man like this around my daughter. Not suggesting that he would ever be inappropriate with her, but that it is not good for a girl to grow up with a misogynist who treats her mother like shit, who has basically turned her mother into a porn star against her will or knowledge.
Finally, I do hope now that you will accept that this wasn't some spur of the moment act of stupidity where he genuinely thought you wouldn't mind or even like it - if he had thought that, he would have told you about it back in February, wouldn't he?! You must know that if you hadn't discovered what he was doing, that he'd continue to keep doing it. I bet what he would've filmed would've got more and more graphic and dubious.
Please stop minimisingnwhat he has done by saying he has been idiotic. Idiotic is putting out the xmas gifts with the rubbish. What he has done is a systematic, well-planned, ongoing form of appallingly abusive betrayal and debasement. It is the opposite of idiotic. It is chilling in its deviousness and misogyny.