AITA for not wanting my fiancé’s cousin’s girlfriend at our civil ceremony?

My fiancé and I are getting legally married this year at city hall/courthouse through a civil ceremony. We are not having a big wedding right now.

Neither of us are American, and both of our families are flying in from two different countries to attend. The current guest list is: his parents and sibling, my parents, my two siblings, and one sibling’s girlfriend.

Yesterday, my fiancé and I got into a fight about the guest list. He asked if one of his close uncles and a cousin could attend. I said yes, because I know they are close, even though I have only met the uncle and cousin once.

Then he asked if the cousin could bring his girlfriend. I said I would prefer not, because this ceremony is supposed to be a very small and private gathering with only close family. I have never met or talked to his cousin’s girlfriend, and from what I understand, she is not close to my fiancé either.

My fiancé got upset and said I was being rude. He also asked why my brother could bring his girlfriend, but his cousin could not.

From my point of view, the situations are different. My brother and his girlfriend live in the same city as me, about a 20-minute drive away, and I hang out with them almost every week. My fiancé has also visited their house multiple times over the past few years. For more context, my fiancé and I are long-distance, and he lives about a 6-hour flight away from me. Also, this is my brother, not my cousin.

Another reason I feel differently is that we are already planning to have a big wedding party in his home country next year or in 2028. He has a large family, around 200 people on his side, and many of them do not have U.S. visas, so the plan is to celebrate there later with his relatives and friends. His cousin could bring his girlfriend to that party.

Honestly, my ideal wedding would have been just the two of us at the courthouse with witnesses. I am a very private person and not really a “big wedding” type of person. But I understand that my fiancé wants his family to be there for the civil ceremony, and my parents would like to attend too. I also understand that he enjoys celebrating with lots of relatives and friends in his home country. That is why I agreed to have a small family gathering now and a bigger party later.

To me, this civil ceremony is not meant to be a full wedding party or a plus-one event. It is supposed to be small, private, and only for close family. I do not feel comfortable having someone I have never met, and who is not close to either of us, attend such an intimate moment.

But my fiancé thinks I am being rude and unfair to his cousin.

AITA for not wanting my fiancé’s cousin’s girlfriend at our small civil ceremony?