Me (28F) and my partner (36M) have been in an open, long distance relationship for almost a year now. Everything has been going really well and I feel like the experience has brought us closer together. But the other day, something really threw me off and I'm having a hard time trusting my partner.

Some background, we will tell each other when we go on dates and if anything physical happens. We've always been upfront about this. He does have a lot of women friends, but I trust him and feel that the vast majority of those relationships are platonic.

The incident - I was on instagram and saw that his sister (who I am not following nor have met in person) posted instagram stories. I decided to watch them and see that his sister and her boyfriend are out to dinner with my partner and a woman that he has never explicitly told me about. I recognized this woman because she had called my partner when we were in the car together months earlier so her name popped up in his car and I creeped because her name had an emoji heart next to it. I assumed it was because he imported her contact info from Tinder, I know the emojis and other profile info will sometimes import when you do that. My heart dropped a little bit when I saw it was her. So I decided to ask him about the "double date". He got a little defensive and said that he feels like I don't trust him because he knows how to interact with other women, but he told me that he was out with a different woman friend that I know of, but I know it was not her on the date. I didn't want to get into it further, so I let it go in the moment of the conversation. However, it still feels like its eating at me. Part of me feels like he said it was the other friend because he didn't want me spiraling out over a different woman friend thinking that it is more than it was, but another part of me feels like I've been betrayed. How do I get over this?

I know I shouldn't have creeped and he told me I should just focus on myself and I'm thinking that's what I do, is just pull back and focus on my own life and my own insecurities.