Should I be worried?

I read my husbands text messages to his female coworker and he was talking badly about me. Should I be worried?

My husband showed me his phone and I scrolled up on his texts with his female coworker. Mostly about working stuff for the first few. Then, I scrolled up and I saw that they were making fun of the fact that I was insecure. She said something about how I'm going to get jealous now that a new hire (female) was going to be in his phone. He replied yeah she doesn't even wanting me calling you by your name just coworker.

I didn't scroll any further but I kind of got a little butthurt.

Her and him are both managers and they often work together to collaborate. When he first got the job I was insecure about her (about a year ago) but later I realized nothing was wrong and haven't said anything about being worried about her.

Now I feel a little weird about their relationship because it's kind of a rude thing to make fun of.

Am I being paranoid?