Boyfriend got mad when I mentioned my old FWB?

Me and my boyfriend started dating after being friends with benefits for a few months. He knew I had one FWB before him that treated me like trash. My boyfriend mentions his exes pretty often. Mainly because one of them kind of ruined his life a few years ago, and sometimes things come up that are hard for him to deal with because of it.

It doesn’t bother me anymore when he mentions his exes because we’ve been together for awhile and I trust him so much. Also, it’s not like he’s telling me how awesome these girls are; when he talks about his exes it’s about how sometimes he has issues because of what he went through because of them.

However, when I called my boyfriend today and we were telling stories to each other, he got mad because I told him about how I told my old shitty FWB before that we may be related when I was drunk (me and my old FWB aren’t even the same race which made it funny). My boyfriend got a weird look on my face and mad a joke about how he was annoyed that I had slept with another man before, but it was obvious that he was actually kind of annoyed and bothered by it. Even though my boyfriend dated 3 girls before me and had sex with all of them multiple times, and I’ve never even been in a real relationship before my current boyfriend and have only had sex with one other guy besides my boyfriend before.

Is it reasonable for my boyfriend to get mad because I mentioned my old FWB? I’m not going to talk about him anymore because I don’t want it to upset my boyfriend, but at the same time I learned to not feel jealous or annoyed when my boyfriend talks about his past relationships. What do you guys think?