Note: I used "cheating" as its making sense to me for my reality I'm reflecting on this term. Here it's mainly for non informed consent and sexual risk for me, I believe.

Edits: 1. *Ex-boyfriend. When I wrote this I was still in shock and realised later that much of this is in present tense. It isn't anymore 2. Clarification that he doesn't have a cheating kink. He has sexual kinks he wanted to explore with others by lying to them that I am aware and didn't ask for their tests.
3. Added more context.

He was cheating on me since Day 1 with 20 folks. He cited reasons as 1. He wasn't sure if he was a priority (please read below too, we were to nest together, introduced each other to our folks he admitted saying this was an excuse to make him feel better) 2. He was jealous of my other partner (he confessed that he thought this could put the onus on me and apologised since it has been non hierarchical and amicable. He said he never was jealous but this was a failsafe because he didn't know what to say when cheating because he's never done it before) 3. He has kinks he wanted to explore (which is healthy and he has sexual autonomy ofc. However he told others that I know about this, but I didn'- creating sexual risks for all people involved) 4. I'm poly (he knew this right when we met, and he conveyed he is monogamous. He always had the autonomy to explore ofc -- but here he equated me being poly to him justifying his cheating ie engaging in sexual relations with multiple folks without me knowing which also increases sexual risk for me and for each of the other partners. He confessed that to say this was an excuse which "made him feel better" about cheating)

We spoke further and he admitted the following too: 1. This was a non hierarchical polyam relationship and he saw it and felt loved. He overthought when alone and wanted attention which he got from outside - he didn't want emotional attention, only sexual (I'm a survivor and it's difficult for me to get intimate regularly). 2. He acknowledged how he was a priority and how this was a serious relationship infact. He's met my brother friends I've met his people, we send gifts to each other's mom's and more. We wanted to nest together because we were serious and we were planning long term life together. He said he didn't feel like he was a priority because of his anxiety and felt better when he got other attention before and during sex (verbatim from him). 3. It was "a lapse of judgement" he had. And it was "only cheating" but he wants to get together again. 4. He hasn't been keeping well, is having panic attacks and needs time to talk because it's affecting him (ie him cheating on me). This is after I told him I'm not okay with the lies and risks and after he saw me having a panic attack (I have triggers). 5. He admitted lying to his hookups that I know of this. And other lies or descriptions he shared with them about me or us. He compared my body to his hookups and such for context.

Idk what I'm looking for here. I do love him but not at the cost of my respect and dignity. Has this happened to anyone? Any advice?