My (23F) BF (25M) has restarted an old friendship with a woman (22?F) after she lost a ton of weight

I've been dating my bf for almost three years. He's had a friend who lives nearly 1000km away that he's known for almost ten years. When we first started dating he would swipe away any messages that came in from her, and when I first asked about her he said she was 'just a friend' and immediately changed the subject. I kind of brushed it off because he's not a very communicative person and from the few messages I saw, they seemed just like good friends. I looked her up on Facebook once out of curiosity and her open profile revealed that she lived pretty far away and was also on the heavier side (probably around ~250 pounds if I had to guess). I wasn't worried either way until around last week when he started hiding his phone more often from me. We frequently use each other's phones to look up sport stats and bike route maps, and I accidentally saw a couple more 'intimate' (I'm not really sure how else to call them) messages between the two of them (he uses an app that shows a preview of recent messages in a conversation when they come in). He had said something about how he hoped she kept her phone off when she slept and that he apologized for potentially waking her up if she hadn't, and that was sandwiched between good night and good morning messages. About a day later we were hanging out again and when he was texting his mom I noticed he had their conversation muted. I had also seen her name in his most recent searches on facebook while he was checking out an event later that same day. I was still thinking of the best way to bring it up with him when I decided to check out her profile again, and realized she had lost a ton of weight and looked pretty similar to me now (build/complexion wise). My last boyfriend had a couple emotional affairs with women online and I had in a moment of weakness looked through his phone before breaking things off, I didn't want it to get to that point this time and I now have a 0 tolerance for these kinds of things. At this point, I'm wondering if it's worth even having that conversation since I'll just come off as crazy/paranoid. Am I being irrational about this?

TL;DR My boyfriend has a mostly secret friend who he has recently ramped up their level of contact, coincidentally at the same time that she lost a ton of weight. Am I being crazy?

Submitted September 21, 2019 at 12:45PM by throwaway3420363456 https://ift.tt/2Ns3jB4