Am I over reacting?

My bf and I share a phone rn since his broke. So he messages ppl on my phone and his co workers. One of his female co workers messages him and their good friends. She talks to him about a lot of stuff and her past. I won’t go into detail but I did read their messages and nothing alarming came up. So when he was getting ready for work I checked my phone again and the messages were deleted. So I asked him why did he delete it? His response was because “the stuff they talk about is private and that I’m judge mental and I talk shit.” Then he said “you don’t wanna hear that she had sex with 5 guys from her last job and that she wants to fuck our boss rn.” Am I being dramatic ? Like I’m really thinking about his answer and idk what to think tbh