The situation is definitely pretty fucked up, and I understand how he could be seen as manipulative, but you guys did invite other people into the bedroom by your initial choosing. It seems unfair that he got to enjoy threesomes and then turn it all around on you, but you guys sound like you should have either broken it off years ago or you’re both really in love fighting for the relationship. The last thing I would accuse him of is being abusive or being “the devil“.