Sounds like we are dealing with different relationship dynamics, but I was struck by something I think we can both relate to.
I have no idea if I will be able to handle seeing him with other girls.
I found out this out for myself the hard way, in the worst possible way.
I had really strong feelings for a friend. Let's call them Skylar. It was Skylar's birthday and for months I told a friend I was planning on telling Skylar how I felt at the end of the party, because without going into detail, I thought I wouldn't see them again after.
We and a bunch of Skylar's friends went out to celebrate Skylar's birthday. Towards the end of the night, it wound up being myself, Skylar and their friend. Let's call them Jesse. At one point, Skylar leans in and asks me "So u/weaksidewing, what's your flow?" "My flow?" "Yeah, your flow, who are you into? I stammer a few answers of mutual friends/ people we know. "Oh, I could see you dating them." But I wasn't very eager to signal my heart was aimed elsewhere. "Well, I mean, I wouldn't date them. Those are, like, two different things."
(Bullshit, I know, but I have anxiety, remember.)
"Ok, so what's your flow?" "That's a dangerous question to ask." Skylar isn't satisfied "C'mon, what's your flow?". "Skylar, that's a dangerous question to ask" I repeat, but grinning.
"Well" Skylar replies "we're together." and they put their arms around Jesse's side, who has been listening to this entire back and forth.
My face feels like all the copper in my blood has concentrated and my cheeks are made of metal. Skylar is explaining the situation pleasantly. Their eyes looking upward as they are summarizing memories and they rub Jesse's back. If I was a more objective viewer, I could call it a fond moment.
Skylar mentions something about how they are dealing with the long distance, and as you might have guessed so far, I leapt on the opportunity to tell a story, though then it was just something for me to focus on other than my own anxiety. After I'm done, the bar closes and they flag a taxi for me to go home. I think I'm fine at this point, but after about five minutes in the cab I'm really antsy. I can really only describe it as a boiling over of energy, and it wants the fuck out.
I get home at 2:30 AM, about nine beers deep and make a decision: I'm going for a run. I made it about a mile before I couldn't run any more, but I had a spot in mind I like to run to when I'm stressed, and I didn't care I had to walk. I wasn't going to be able to sleep. I've looked up the distance since; it's seven miles there and back.
I do eventually fall asleep, and I'm given a little reprieve. I'm laughing because apparently having a nervous breakdown and running at 3:00 AM is a great hangover cure. I honestly felt pretty good for someone who had only four hours of sleep. However, I didn't want to sit around in my apartment, so I go to the local coffee shop, and just try to focus on something else, but I can't. I wasn't angry with them. I grew up in a very abusive household, and I couldn't articulate why then, but I consider them, Skylar, like family. Or close to family anyways. I wanted to tell them about my mental condition. But there was a problem: While we were out celebrating Skylar's birthday, it was actually for a few days; and I didn't have any intention of letting that taint their birthday.
I had told just one other person before then. It was through text, I thought I would never see them again, and they helped me even though they couldn't have known because I didn't know what was wrong then. I remembered in the coffee shop what a fucking relief it was to tell someone. I have very strong feelings about not telling people because you think it will burden them, but I just couldn't do it to Skylar then. Didn't seem right. So I thought about others who helped me like Skylar did, and I told them (I know this sounds like bullshit but the coffee shop was playing the Beatles and "I get by with a little help from my friends as I told one friend"). I Resolved to tell Skylar sometime later.
But I knew I would be seeing them before their birthday. We were walking together the following monday when they ask me,
"So, u/weaksidewing, what did you do all Sunday?"
I'm smiling because, given the context that I had in my head and you have now read, it is histrionic and cheesy af, but I say it anyways.
"I recovered."
When I see photos of them together, still makes my stomach churn, as if it too has eyes and wants to look away. But Skylar is a really good friend, and there is a least a part of me that wants them to be happy that I know won't make me happy. Still working on the healthiest way to go about doing that. Maybe I'll be able to let you know how that goes.