Yes, I have to agree with your T, with one caveat....I did the same thing....years ago...just to 'understand' and gain 'closure'.....and eventually, for me, it turned into also wanting acceptance and since he was so good at being good when he wanted to be, he turned on the charm and I went back.......to 2 more months of horrendous abuse. I left for the last time and never looked back.

Not to say what he is doing will have the same result, but honestly, if she is an ex, whilst talking occasionally is totally understandable....regular weekly, long texts seems a bit excessive to me. It would definitely be so for me, were it my bf. She is an 'ex' for a reason and unless he wants me to join the club, he needs to cease and desist. Somehow, I don't quite believe her new bf would entirely appreciate the attention she's paying to HER ex either.

IMO you should stop being so 'understanding' of the shoes he's walking in, and say what you feel instead of allowing resentment and concern to build up to the point you're asking your T to explain why it's okay for him to do this, and cause these feelings your having in the first place.

In other words...TELL him, it makes you uncomfortable and that the constant texting is inappropriate. Period.

THEN if he goes on the defensive....you have an issue worthy of asking your T about.

Take care....