My cheating bf thinks we are “even”

My bf(22m) and I(21f) have been together for over a year. When I met my boyfriend, let’s call him Blake, I had just started “talking” to an old friend of mine, and we went on a date. Fast forward, I had been on 2 dates with Blake, and decided to go on one more date with my old friend. I have always been a “date around” type of person and I am transparent about that. They both knew I was not exclusive to them at that time. I decided I could see something long term with Blake so I stopped seeing my old friend. I texted him and said “I don’t see this going anywhere, romantically or physically. I’m sorry.” He told me he wouldn’t pry and that he understood. He asked if we could keep texting the way we used to (when we were just friends) and I told him no, not for right now. One month into my relationship with Blake, my old friend calls me, very upset, and tells me how much he misses our friendship. He tells me that he’ll respect my decision that there will be nothing romantic or physical, he just wants to be friends again, the way we were for years prior to exploring any attraction. He was crying on the phone to me and I didn’t have the heart to tell him I had a boyfriend. I told him if he wants to text me every now and then as friends he can. We would send memes, talk about TV shows we love, politics, whatever. NOTHING was every physical or flirty.

However, I did not explicitly tell him I had a boyfriend until 2 months after we became friends again. I know it’s wrong, but he told me how hurt he was by us not speaking and how he had strong feelings for me before I ended things. I just felt awful. I know how awful that is. I felt really guilty. 2 or 3 months after I was honest with my friend, my boyfriend snooped through my texts and found everything. He thought I was trying to keep the door open for a future relationship. I tried to show him proof that it was my shitty way of protecting my friends feelings (texts with other friends saying things like “I know it’s going to crush *old friend* if I tell him but I know I have to.” My boyfriend then started saying that was putting my friends feelings above his and that is a horrible thing to do. He requested that I stop talking to my old friend, remove him on social media, etc. I told him I would stop talking to him. I felt like that boundary was controlling but I didn’t say that. Instead I just responded to my friend if he texted me first, gave one word answers, things like that. He asked me if I had talked to him at all recently and I said “I did like a meme he sent me on instagram and I think I reacted to a text he sent. I’m sorry” He snooped again and found a couple short replies and he freaked out, calling me a liar because instead of liking the message like I said, I replied “haha.” I genuinely did not remember the specifics of what I said to him and in no way lied to make things sound better than they were. He asked again that I never talk to my old friend again and I listened. We haven’t spoken since.

9 months later, my bf starts acting weird with his phone, claiming he started believing in more phone privacy in this relationship. I already had never asked to go on his phone, didn’t know his passcode, never snooped, etc. Red flag to me. He is friends with an ex-hook up buddy and tons of girls he’s had crushes on or briefly dated, so that’s always been in the back of my mind. One day, against my better judgement, I snooped. I found texts with his ex, 3 days before he asked me to be his girlfriend, saying “Hope this girl and I don’t work out then I can f**k you again” and tons of very sexually explicit texts. She told him to “put your side wh*re where she belongs and fuck your main wh*re. You have to fuck me anyway you know…” and he “hearted” the message. He claimed he was exclusive to me from our 2nd date, but was doing this sh*t. Then, 3 weeks into our relationship, and the day I left for a trip, he asks if she is still in our city and asks to hang out. She says no and he replies “:( I miss you I wish I could have seen you.” I showed him the texts and his initial response was “To get this upset about stuff that happened before we were dating is actually insane. You did this to yourself by snooping.” He then wove this whole story about wanting to play along to not hurt her feelings, but he texted her first. I told him I felt like he cheated on me and his response was “If I cheated then so did you. I have a hard time feeling sympathy for you when you did the same thing to me.”

We are still together for the time being, but he keeps treating these situations like they’re equal. If I tell him I’m feeling triggered by what he did, he says something like “Well I’m feeling really hurt by what you did to me too.” It has been months since I found out what he did and I feel so unsatisfied with his attempts to comfort me. Has anyone else been in a “double betrayal” situation like this? How can I get him to see that this isn’t me vs him?

TLDR; My (21F) bf (22m) thinks my lying and his cheating are on the same “playing field” and won’t stop treating it as such.