I (26F) got jealous of my boyfriend’s (28M) close female friend (23F)

Recently my boyfriend (28M) and I (26F) had a problem of jealousy and concern from my side. We’ve known each other for 5 months, in relationships for 3,5 months. We meet pretty often, at least 2-3 days a week. He’s a sweet and nice guy in general. And I don’t know if I’m being unreasonable and too sensitive…

My bf took his female friend (23F) that I’ve never met before on a last minute day trip without letting me know or inviting me with them. I found out later that day when I checked in what he was up to and he said he was on a day trip with his female friend. I got very upset and angry because he obviously hangs out with her alone often without telling me in advance. Dinners/ice cream/day trips and I never knew about it. A week before the trip, he went out with her for a dinner (again, I had to check in and ask what he was doing to see if he wanted to get dinner with me, for him to tell me he was with his friend) I told him I was upset that he didn’t let me know or invited me to join them. Later when we got to talk, I asked to be introduced to her just to get to know her for myself, to which he said he thinks it’s a bad idea because she is an awkward person and it will be weird for us to meet because we don’t talk about relationship stuff.

I said I don’t feel comfortable with them going on trips together, or alone hang outs that come off as couple dates that we usually do, or where there are no other girls/guys. Like picking her up to go get dinner and dessert and all of that. Maybe I would’ve felt different, if I got to meet her, but I don’t know. But supposedly they don’t have any common friends and never introduced each other to their own friends so they hang out just the two of them. So not meeting alone goes out the window. He claims he’s not jealous type and if I ever hung out with guy friends or went on trips like that, he would not have a second thought. Even if the other guy liked you. (Wish I could be that secure lol)

I personally do not have close guy friends anymore, (with the exception of one guy friend who is from the same home country as me and I made sure to introduce him to my bf on my birthday party. Plus we don’t hang out alone anymore since we’re both in relationships and are respectful of each other’s partners) Because it often happened that guys I thought we were genuine friends with had crush on me and would later on tell me about it. And if I go to meet my friends, I try to tell my bf ahead of time and invite him with me, especially if there are ever any guys in the group. (Which is not common) Yesterday, my bf said his female friend invited him to get dessert and asked if he can go or if I will get mad at him. I just said to have fun and say hi from me. But then, they ended up getting dinner, dessert, went grocery shopping. It’s eating me from inside and I’m upset…

So, because my bf refuses to introduce me to her, it raises different unwanted thoughts in my mind. And when I asked him, “do you not want me to meet her because she might like you and will feel hurt?” He answered that they have already talked about possibilities of relationships between them. And when he asked her if they were just friends or want to be more, she said “yes, we are friends”. Which also does not put my mind at ease. I’m his first “official” girlfriend so I’m trying to give him a benefit of the doubt that he just doesn’t understand. But at the same time, I only had one longterm relationship before him and try to make sure I think about my partner’s feelings. And if I do mess up I try to change it and help them feel better.

I understand that if someone will cheat, they will cheat no matter how many precautions you put in place. And now I don’t know if I just made myself look like a psycho girlfriend and spoiled this relationship.