Both FI and FMIL have recently talked to me about a party the day after. FI's brother and sister in law hosted their own day after party and invited both families (aunts, uncles, cousins also). Her extended family is a total of 10 people so there were not too many people from her side.
FI's family is large and very close. Everyone who is invited will come because that is the nature of the family. All of his cousins are in the wedding as well. When you add up my extended family and his extended families, plus friends in the wedding party, it is over 85 people!
FMIL says that we have to have this because it is tradition and "you know how close our family is." Personally, I do not want over 80 people at my house ever, in fact, it is not even close to big enough for that many people. I especially do not want to worry about 80 people at my house the day after my wedding. Also, why would I want to put all of those people through us opening gifts? Also, how is having something one time a tradition? None of his other cousins has ever done this after their weddings.
I told FI that I do not want to do this. He understands but says that his family is expecting it. I said that if his family is expecting it then one of them can host it. I do not want to deal with it. I suggested that just the wedding party, parents and his grandmother be invited. That is still over 30 people.
Am I being unreasonable? Can I refuse to have this? Does anyone have a better solution?