First big fight w/ my bf-long

First and foremost, thanks for reading this. It's a rant. I have a lot of things on my mind about my relationship currently, and what better place to anonymously rant than the internet? Lol. I apologize for any spelling and grammar errors.My partner (let's call him Mick)(23, m) and I (23, m) started dating last October. I just moved to the state to finish school. Mick was studying Crim at the school. We first made contact via Grindr (I know). Things didn't fall into the sexual realm. I wanted to find more connections and potential friends. We met and hung out once a week throughout October. We learned more about each other and long short, we fell for each other.Mick and I became official in December. Our communication had a strong foundation. I put in effort as did he. Early on he confided that he was new to the relationship thing (as I was his first boyfriend). He openly discussed how he has Bipolar II. He's unmediated and seeks alternative coping mechanisms, which are pretty successful. His mood swings don't mirror those you often hear about. I have anxiety and a recent history (past couple years) of sexual and emotion abuse. I'm also a recovering codependent. I'm currently seeing a therapist every week which has been wonderful and helpful. Mick and I have been open about these parts of our lives).Mid October, Mick hosted a Christmas party for some of his friends: one of whom is named Seth. Seth is engaged to a guy named Brad. Two days before the party, Mick told me that he had sex with Seth and Brad before (once with just Seth, and second time-a threesome). Mick said they were one offs-he wasn't attracted to them.-they were drunk, etc. Things didn't really sit well with me. Mick explained his first encounter with Seth and implied that Seth 'took advantage.' I expressed my concern...it seemed on the verge of a nonconsensual encounter, but Mick brushed it off. Mick stated that he didn't speak with Seth for three months. The threesome happened sometime after that, which Mick initiated after another drunk encounter. Mick refers to Seth as his BEST friend.I opened up to Mick about how I was feeling after hearing all this and more. I asked how he was feeling. I checked in. Mick stated and implied at the start of our relationship that when he parties and drinks a lot, he relies on friends to take care of him and 'shut him off.' In short: he used/uses alcohol as an excuse for his actions and to deny responsibility. It's hard for him to accept responsibility. He does, but it can be a little slow. I've remained firm with my boundaries of being caring without neglecting my own health.Back to the Christmas party-things went fine. Seth and Brad invited us to their place a few states away.Fast forward to a month ago (late June). Since the Christmas party, Mick was adamant about 'us' going to see Seth and Brad. Their past sexual encounters made me uncomfortable, but I was determined to put my own insecurities aside and support Mick. Suddenly, Mick changed his tune. He was adamantly stating that he was going to see them and if I wanted to 'tag along,' I could. He was extremely inflexible and stubborn.I called him out and asked him about the situation. After a day and a half of some awkwardness, he opened up and explained that he really needed friend time. He wanted me to go. I told him that if he wanted to go and see them alone, that would've been fine. His behavior and how he communicated it all to me wasn't cool. It put me through the ringer. I wasn't super comfortable with him going alone to Seth and Brad's place alone, but I left it and recognized it as one of my insecurities peeping through.The weekend arrived that Mick and I drove to see Seth and Brad. Since we awoke in the morning, Mick was up my ass about everything and constantly snapped at me. I asked him to please not snap at me...I had done nothing to warrant it. I didn't want to start off the weekend that way. Mick got the hint.We arrived and things became very pleasant. Seth and Brad were good hosts and were friendly. That night there was a lot of drinking. Brad and I had a couple. Seth and Mick got pretty drunk.Early in the night a discussion came up about gaming. I have an ex that was a semi professional gamer. We were not on good terms, but I did get some good gaming stuff out of our short time together. Mick knows about this. He somehow missed one if the details. He got annoyed. I tried to jokingly soothe him by offering my hand for him to playfully bite (he's a biter, and I like it. He knows my boundaries well). Instead of being playful, Mick bit me very hard to the point where I slapped him. All he gave was an apathetic sorry and a "then don't put your hand there."At one point I was sitting on the couch next to Seth and the discussion arose about a wooden paddle nearby. Somehow the question of whether or not it hurts more on bare skin popped up. Seth had tried using it on Mick over his shorts, but I politely stated that I'd take a couple swings.Seth pulled Mick over his knee and on top of me and made to pull down his shorts and underwear. Mick was completely compliant, arms over his head, crossed. I was a little in shock. Seth then paused and asked me:"Are you ok with this?"Me: "I'm uncomfortable."Seth: "well, this is awkward...(doesn't move)"Brad: "he said he was uncomfortable, respect that."I was extremely uncomfortable. Mick and I are monogamous. Seth and Brad are not. Both Brad and Mick agree that Seth can be a little handsy and pushy sometimes. The night continued and I excused myself for a few. At several points Mick asked me what was up. I explained three simple points as to why I was uncomfortable:He and Seth had a sexual history. I was not okay with Seth pulling down his pants and spanking him. I explained that if it hadn't been on top of me, I wouldn't have intervened.Mick made no move on his own during the situation-leaving it up to me what happened. I was not okay with that. Every indicator he gave off said he was fully aware and ok with what was going to happen.If our positions were switched, Mick would have flipped.I kept calm and stated that we could talk about it more the next day. I didn't want to be the dead weight that weekend. Mick kept asking me that night and each time stated that Seth was his friend, etc.Later that night, Mick and I fought. He kept playing the victim stating things like, "if I'm such a bad person..." I chose to walk away. Mick told me he wished he came alone; that he knew I would be a downer this weekend. It was one of those situations where I was crying outside at 2am talking to my best friend.The next day, I came to several possible conclusions:The weekend was a test of my boundaries with Seth, Brad, Mick, and possible sexual stuff.That Mick may or may not have an interest in drunk sexual situations that he would be ashamed of while sober.I didn't bring these up to Mick. I was polite and cordial. Mick tried to hug and hold my hand several times that day. I declined. I told him I wasn't feeling affectionate. I was done having to explain and give answers. He didn't understand that I was dead serious about the night before. He had physically hurt me and then had pushed my boundaries again. Mick was like a beaten puppy for the rest of the day.That night he broke down and apologized. he wasn't fully sure what he had done. I was a bit pissed. I decided that this would be the last chance and I explained how he had treated me like crap since we woke the morning of the trip.Since then, things have smoothed over. I still feel really rattled about everything. I feel like I can't fully trust him. I feel like the big bad wolf in that maybe I was 'overbearing.' Then I think of things he said that was uncalled for and how I just took it and took it, not wanting to bring it up and ruin the weekend. Mick was indirect with me about everything.Anyway, thank you for reading. Comments are not needed but they are appreciated. This is Mick's first relationship, and my second. This was our first big fight.