Sexual Safety Informed Consent Issue
I am a 39 year old bi cis woman and I have around 17 years of experience with non-monogamy: 14 years in a polyamorous nesting partnership with my ex, during which time we both had several other relationships, and then since we split up 3 years ago, I have had some shorter term open/poly relationships.
For the past year I have been dating a poly married cis man who is a parent and it has been really pleasant. I don't feel super in love but I appreciate and enjoy the sex and companionship and the relationship has fit well into my life. I am committed to some demanding career stuff right now and prioritize time with friends, so I have enjoyed having a thing that is consistent and familiar and fun but not super time consuming. Early on we agreed that we could have unprotected sex because he has a vasectomy and his spouse (nb, they/them) has one other partner (trans man, they/them) who was not having sex with anyone else and I wasn't having sex with anyone else and we had all been tested so it was a closed loop with no real risk. We agreed that if any part of this dynamic changed we would disclose and potentially renegotiate safe sex practices.
It is a very sweet kitchen table situation and we all hang out in a group occasionally and do family stuff which has felt nice and fun! I genuinely really like his spouse and their other partner and the kiddo.
Recently he told me that his spouse's other partner had been sleeping with other people for awhile, like a month, and that his spouse was planning to get on Prep and DoxyPrep to minimize the risk of STI transmission. I was pretty upset that he knew that this had been happening for a month without telling me, while continuing to have unprotected sex with me. He said that his spouse's partner has been exchanging test results with people before sex as a safety measure and that he meant to tell me sooner but it slipped his mind and he didn't think it was a big deal at the time because he trusts his spouse to have safe sex. I feel like if the circumstances and plan had been discussed with me prior to exposing me to increased risk, I *might* have been ok with it, but since it wasn't, I feel a big loss of trust and like my agency to give informed consent was compromised.
He has apologized genuinely and promised to communicate better in the future. He and his spouse are new to polyamory, I am his first outside relationship. Part of me feels like this is a pretty huge thing to mess up and it makes him seem kind of clueless and careless which is unattractive. Yet, I understand that people make mistakes... My ex violated safe sex agreements several times over the years and I always forgave him and did so much emotional labor around it and often ended up feeling really disrespected and resentful and I pretty allergic to that dynamic as a result. I have had other partners in the past who were very diligent about communicating about their sexual activity with others and adjusting our safe sex practices in response and it was so hot and made our sex life even hotter! So I know it can be done well and I have that hope and expectation.
It would be sad to dump this person but I am considering it! Any suggestions for a plan to propose in order to rebuild trust? I feel torn between not wanting to be harsh and perfectionistic and give up a nice thing and also just feeling like ugh I do not have the energy to help this guy figure out how to do a very basic communication thing.