Open relationship and boundaries. Am I overreacting?
Partner and I opened our relationship since we are away from each other. The arrangement goes like this, you send a photo and confirmation that it's okay to hook up with this person and the other person approves. We do oral only or fuck others, never to be fucked. I even asked if it's okay if I join recon out of respect.
Now this weekend, my partner found a guy and told me literally an hour before he was supposed to arrive at his place. I told him it was fine and had to ask for photos of this guy. He hooked up and said he felt really slutty during the arrangement. So much so, he was okay with being fucked by this guy but the guy had a hard time staying hard. This guy has a small/average penis which made it okay for him. Now my partner only told me this after the fact.
My reaction was this: upset. I told him this was a boundary for me which he knew, and he almost crossed the line. My partner and I haven't fucked in over a year because it's never a good time for him. He claims whenever we are together we eat spicy food which his butt can't handle which is partially true. He also claims my dick is too big which isn't true. I'm pretty much just 6 inches or slightly more depending on the day. We have bought toys to help him prepare beforehand.
Anyway, when I confronted him about this he gave a list of excuses as to why we don't fuck like the above and said it takes a lot more preparation to be fucked by me vs someone smaller. Then he tried to place the blame on me, claiming I'm too rough (I have listened to him guide me while I was inserting it so I do listen and try to be gentle). When I told him he never seems interested in fucking with me he tried to blame me by saying I should've bottomed for him.
Now he's telling me that he's feeling more energetic with his body this year and wants to try bottoming for others before doing it with me? This is news to me.
We've been together for like 3 years now. Early on in our relationship during a grey period he did cheat on me once and lie about being on recon. He confessed to me days after I confronted him. So I do have trust issues with him still but he's been pretty open about everything until now.
Do I end things with him? How do I move forward at this point? And I apologize for the length.
TL;DR: my partner almost got fucked by a stranger because he was in the moment even though it's a clear boundary for us. he's cheated once early on in our relationship so i have trust issues.