Suspicious?

So me and my SO were talking about how cute my cousins baby is, I was telling him I saw a video she posted and that he was learning how to crawl. And he says "yeah hes getting big, she told me he fell off the bed the other night "

And I'm like.... oh did she? When did you talk to her.

Because last time we saw her was for new years and we dont talk, we aren't close

And if I'm being honest she is one of those people who just throws herself at guys not caring who she will hurt.

And well I asked him again because he said "you're crazy and get jealous for nothing"

And I told him if its innocent just tell me when you talked to her like, he doesnt need to get all suspicious.....

But in the end I'm laying in bed, HE is MAD AT ME. And he didnt tell me anything, just ignored me after I asked him again.

I've never had any reason to not trust him but I have a weird feeling and I dont know what to think because I asked and he ignored.