<human>: Provide a brief overview of the text.

We have been dating for four, and this is the first relationship I have been in that I feel we both are putting the same amount of effort into and we treat each other as equals. 
When we first got together he told me that he still talks to his ex but very rarely and the conversations they do have are stunted and awkward. 
Recently we went through a stressful work situation (we moved two provinces away for work but the work wasn't there). While we were there I saw that his ex's name was in his inbox and recent calls. He has also been more secretive with his phone, when normally he never cared that much. 
They broke up two years ago, but had a few booty calls since then, the last one being seven months before we got together. The reason he told me that they still talk is that he feels sorry for how her life went after they broke up. She got addicted to cocaine, got drunk and stoned at a party slept with some guy she didn't know and got pregnant. From what he has told me what they had sounded pretty toxic, they fed each other's addictions, had nothing really in common, the first time they slept together she was in a relationship with someone else.
I just need help on how to bring this up without it becoming a huge fight. I trust him but I know that when he is feeling shitty or depressed he can make poor choices (he has even told me that himself). I really do not want this relationship to end, but I really struggle when it comes to opening up about issues that bug me.
<bot>: I think my boyfriend is talking to his ex more than normal and it makes me uncomfortable and I want him to stop.