Bf being wierd

My boyfriend reached out to his ex from years ago and has been talking to her about our entire relationship, good and bad. Also told her how he loved her and was reminicing on memories with her. She didnt seem very interested when he would make those remarks in the chat. He told her if she needs anything at all hes at her service... wtf? He said its because shes going through alot too. He also told her personal details about our sex life. I asked him why would he do this and he said its because he has no one to talk to about this stuff. Well neither do i but im not reaching out to my ex. He said he only reached out because him and i were having issues and he wanted advice from her on how to fix it because shes very smart. He was over lastnight and he was texting her while he was here. I had taken a picture of him and his son while they were here and he sent it to her . I asked why and he said he wanted to show her how much he loves his son and it was a good pic. But if you were only talking to her to see about advice why are you reminiscing, sending pics and talking about other things. Like i said she didnt seem interested i read all messages and was upset and then he threw his phone in the toilet. Wtf to think