I (31 F) am getting married in a few months. My fiance (31 M) and I both have a large number of aunts, uncles, and 1st cousins - and many 2nd cousins. Fiance is in the middle of medical residency and I am a non-profit lawyer (big student loans but not big salaries).  We saved enough money to host a lovely reception at a venue with a 266-person seating cap. Every other venue close to the ceremony was 10K-15K more expensive. We purposely booked venues close to our families (we presently live an 8 hour drive away), got married in a city with both an airport and a direct bus line to a cheaper airport, and planned everything so that once our guests arrived, they would not have to drive from one location to another (ceremony/reception/hotels all within 2 blocks, and we hired a trolly in case of mobility issues). Internet wedding websites dictated that usually ⅓ of invitees decline, so we gambled and invited 320 people. We split the list so we got ⅓, my parents got ⅓, and my future in-laws got ⅓ of the invites. We had a no-kid wedding to so we could include as many adult family members, career mentors, and close friends as we could. The one exception to the no kid rule was for first cousins - the youngest of whom was 16. Our parents got together and decided mutually to not invite the children of our first cousins. I was apprehensive about this, because there were 3 2nd cousins I felt weird not inviting, but that would have added 30 additional invitees (20 2nd cousins and plus-ones for the 10 that were adults in relationships), plus it would have further muddied the no kid rule. We sent invites stating it was a no kid wedding and that we had rented a suite at the hotel and hired babysitters (my future SIL’s colleagues at a preschool) should our guests want to take advantage of close, free childcare during the wedding and reception. No one objected until last week, when my aunt sent her RSVP, marking down her granddaughter (17F) as her plus one. Before we even had a chance to discuss, my aunt called my dad to argue that her grandson should also be invited. She stated that he was the only person in his immediate family not invited, he was 18 and not a child, and we should not have to exclude him. My father reminded her that her granddaughter was not invited, and not a single child of a first cousin had been invited - categorically, even if they were legal adults. She responded that her son and daughter in law were offended and expected us to change the guest list. When my parents refused, they requested we amend the invite to include their son instead of my actual cousin (his father). I dug my heels in. I felt this was extremely rude and I did not appreciate my father calling to yell at me because he could not handle the pressure of his sister yelling at him (my dad and his sisters are generally fairly emotionally immature). So I refused. The cousin at issue is 14 years older than me and male, and I grew up in a different state. There is no reason we would have been close. I do remember that after he got married, his wife immediately took to trying to change well established family holidays instead of just skipping the event if they had a conflict. Our grandmother was nearly 90 and in poor health and we all knew there were only a few holidays left, but she kept pushing to change times and locations until huge blow ups happened. For example, one year due to her urging, we bumped our typical Thanksgiving meal time from 12:30 to 11:00. When I was 21, had to leave from my college in another state at 5:30 AM to give me enough cushion to get there in time. However, there was a car accident on the way down and I arrived at 11:20. Even though my cousin had nowhere to be after the lunch (raising the question, why did we have to change in the first place?), he, his wife, and my aunt insisted that I was being disrespectful and that they would not delay (honestly I would not have cared and much preferred everyone just sat down to eat and didn't fight about it). This caused a multigenerational fight, wherein basically everyone but them thought they were being unreasonable and told them to get over themselves. I dont really remember how they treated me once I did arrive but the whole thing did not need to happen. There are a ton of other examples of this cousin showing up places (will reading, funeral home to help choose my grandpa’s casket, etc) against my grandmother’s wishes. This just feels like another attempt to exert control over something that has absolutely nothing to do with him and I am not having it. My parents want me to let my aunt bring her granddaughter because we did give her a plus one and it would seem demeaning to not let her choose who she brings. She says the reason for this is she wants her granddaughter to make it through college (she has a full ride at a good school so I am not at all concerned she would drop out once she starts) and that seeing what kind of wedding you can afford when you graduate and focus on your career will motivate her. I am considering this (even though I think the reasoning is really weird and, again, she has a solid academic record even though her parents did not go to college - I think she will do just fine without ever meeting me in person, let alone witnessing my wedding) but am absolutely not inviting her grandson (who i could not pick out of a crowd to save my life). AITA?