I've been with my husband for 4 years, been married just a couple months and have a one year old together. We had a very off again on again relationship until the day we found out I was pregnant in 2016. We've been steady and happy with each other ever since, until last Saturday. On that day he got a text from a girl that he had sexted with when we were fighting in 2016. She goes on to share pictures with him that he has sent her all those years ago. She asks him if he wants to hook up and when he says hes married she doesn't have a problem. He told me he was scared she would post the pictures everywhere and he needed to find a way to "let her down easy". At first I was just laughing at how uncomfortable he was and I'm very secure in my marriage but then I found the messages yesterday. He kept talking to her and they sent pictures to each other. I have absolutely no idea what to do, I don't want to even look at him but I can't bring myself to tell him I know. I feel like it's my fault, if I had been enough for him he wouldn't be telling another person that they make him horny. I feel like breaking his face one minute and then so depressed that I'm just gonna tell him to go with her.

Edit: thank you for the support, I really feel as if you ladies have my back. I do believe this is my fault. I'm also realizing that I'm not secure in my marriage like I said earlier or i would have had the balls to say "block that skank now!" I lost all my fire when I had my son and now I'm at the point with my body image that I dont blame him for wanting a 23 year old that doesn't have saggy boobs and a stretch marked stomach. I know in my heart of hearts that this isn't ok but I don't have anywhere to go or a way to support my son.