Don't know what to do

Priscilla
My boyfriend (Thomas) is no longer with his wife (vanessa) for about five years cause she cheated on him with her now boyfriend of 4 years I think (Lauro). We've been together for about 2 years. Thomas and vanessa have a daughter who is 8 years old. Vanessa and Lauro have a 1 year old and a baby on the way. Well Thomas and Vanessa are still legally married and the reason he is saying is cause he likes that he can see his daughter whenever. Fair enough. Well i recently found out Vanessa cheated again with a guy from Thomas and Vanessa's daughters school. She had been hooking up with him since her and Thomas had even been married and the baby she's pregnant with isn't her boyfriends, it's the dad of Vanessa and Thomas's daughter classmate. And Vanessa is using Thomas's name for all the medical bills and everything with their house that they still own legally cause their married still. My boyfriend doesn't know this cause I recently found out from my boyfriends daughters friends mom. She heard from the PTA moms and it's just so embarrassing. I don't know what to do. He will either get mad I'm gossiping with the mom or I'm just jealous.