Boyfriend (m28) in Japan, I’m (f29) feeling left out.

One of my boyfriend’s friends is getting married and planned a trip to Japan to celebrate. He called it a bachelors trip but the fiance is going. In a group of about 9 people, 5 of them are married and the other 3 are single. My boyfriend is the only with a girlfriend (me.) Another factor in this situation is that 4 of the married couples are in grooms in the same wedding. The rest of the group is all friends with grooms brother, including my boyfriend.

I felt a little bad that I wasn’t going but he told me I wasn’t invited by the groom so I left it at that. But when he brought me around his friends, they were asking me “are you going to japan?”

This made me feel uneasy because why would his friends ask me if I’m going to Japan if my boyfriend told me I wasn’t invited?

I confronted my boyfriend on this and he told me that they weren’t the ones planning the trip, it was the groom and he didn’t know me that well. By the time the groom told my boyfriend it was ok for me to go, they had already bought their tickets and it would have been a hassle to buy mine. He also said that nobody else is bringing their girlfriends, they’re all wives and I’m not a wife. We’ve been dating for only over a year. He’s on the trip right now and I’m not trying to pick a fight with him or anything but I feel really hurt and left out. I think the truth is he just didn’t want me to go and he didn’t want to admit it.

Some things I’m trying to consider. He takes responsibility of me when we’re together and maybe he didn’t want to me to go because he didn’t want to worry about me? I really don’t think he’s doing this to cheat on me. My boyfriend is also already having some financial troubles and was scrambling to pull money together until the very day they left.

My cousin tells me she would be really hurt and consider breaking up with him over this. My dad is siding with my boyfriend and telling me I’m overthinking things. I’m not sure how I should be feeling and it’s making me question the relationship. I need some confirmation so I can just put this to bed and not worry about it. :(

TL;DR bf went on a trip and told me i wasn’t invited but his friends were asking if i was going. i found out that i possibly was invited on the trip, i think he just didn’t want me to go. i dont think he’s cheating. don’t know how to proceed.