Husbands first love & sex talk

What would you do if your husband was talking to his first love about each other's sex life? They didn't officially date, but they kinda thinged it and he loved her. He is friends with almost all of his exes and I'm ok with it most of the time. But I saw he was texting her about our sex life and she told him about hers. This really isn't sitting right with me and bugging me bad. I already flipped in him a little. She especially gives him details, what they were doing, what they did to each other, where they did it. What would you do? Please help.