Q&A How Do I Bring up a Situation I'm Uncomfortable With?

My husband and I are 7 months out from our d-day. Things are going well overall. However, I recently had a paranoid moment and went through his phone without him knowing. I found an ongoing conversation with a woman he went to high school with. I didn't see anything inappropriate, but I could tell part of the conversation had been deleted, as it only went back about 2 weeks, and I know they've had ongoing conversation off and on for years. I don't suspect that he is having another affair, but I do think he deleted it because he knows I'm uncomfortable and triggered when I think he is seeking validation from other women. I want to talk to him about it because I don't want anything being hidden or deleted ever, but I don't know how to start and have the conversation.