AITA for asking my partner not to stay for the evening part of his cousin’s wedding since I wasn’t invited, and for not wanting to invite her to our future wedding?

I (35F) have been with my partner (38M) for over five years, and we’ve lived together for the last two. I’ve met his entire family, and we have a good relationship overall. His cousin, who he was very close to growing up, is getting married next year. She moved to Singapore a few years ago but is coming back to the UK (about an hour away from us) for the wedding.

We’ve only met three times due to the distance, but we’ve always gotten along. We follow each other on social media and have exchanged messages here and there. She recently sent out wedding invitations, and while my partner was invited, the invite explicitly stated “no plus one.”

I initially assumed it was a very small, intimate wedding—until I found out it’s actually a large celebration with around 200 guests, and all the other family members’ partners are invited. I’m literally the only long-term partner who was left off the list. That hurt.

I asked my partner if he could check with his cousin to see if I could just come to the evening reception. I said I didn’t need a meal or anything, I’d just like to be there to celebrate. Her response was that they’re already at full capacity. But I know for a fact some guests can’t attend, so that felt more like an excuse than the real reason.

I genuinely don’t understand why she doesn’t want me there. Our interactions have always been pleasant, and after five years with my partner, I figured I’d be included in something like this. If we were only a few months into the relationship, I’d totally get it—but five years feels significant.

I told my partner that, while it’s obviously her choice who she invites, the message is clear: for whatever reason, she doesn’t want me there. I asked if, as a show of support, he’d only attend the ceremony and skip the dinner and evening celebration. I’m not asking him to skip the entire wedding—just not to spend the whole day celebrating with someone who excluded me. He said I’m putting him in a difficult position, which I do understand to some extent, but I also feel like I’ve been put in one too.

I also told him that, if and when we get married (something we’ve discussed for next year), I don’t want to invite her. He said that’s childish and that we’d have to invite everyone in his family. But we’ll likely have a small wedding, and I don’t see why I should extend an invitation to someone who made it clear she didn’t want me at hers.

So, AITA for:

1.  Asking my partner not to attend the evening part of the wedding out of solidarity?

2.  Saying I don’t want to invite his cousin to our future wedding?