Can someone please help me

So today I was hanging out with my boyfriend and we both ended things with our exs pretty bad and when we first met we were helping each other get over them my ex had dumped me then threatened to burn down my house and carved my initial in his chest told me to kill myself and spread rumors about me around school after he dumped me and while we were dating it was just an overall toxic relationship my current boyfriends ex had cheated on him and had an orgy in a bathroom and now today we were having fun eating dinner and joking around and I went to get more food and when I came back I saw him texting his ex... I'm not a crazy girlfriend, he texts his other ex and I text mine sometimes Bc we know it's jut friends but we had each agreed to block our crazy exs and now that somehow she's unblocked and their messaging bothers me but what bothers me most is that he didn't tell me about it and I don't know how to approach him and ask him about it....any ideas?