I am having a destination wedding in Europe where we have rented a house that can accommodate up to 36 guests. We had to be very strict with the limited guest list and there are a lot of disappointed family members on both sides. I had invited my aunt’s (by marriage) mother out of courtesy to a kind lady who has known me my whole life, but she is elderly and cannot attend. Her adult son (who lives with her) is asking if he can take her place. He was not named on the invitation but I am getting a lot of pressure from my aunt that since we have not received enough RSVPs (so far) to fill every single bed in the house, his taking the place of an invited guest is “no big deal”.
Even if there is technically a bed for him, some people are already sharing rooms and having a little space would make things more comfortable for all. I am also not comfortable letting him attend the wedding when his two other brothers (who I know just as well) are not invited. Also, there are other closer relatives that I would prefer to invite if there was room enough. And in the end shouldn't people know that wedding invitations are none-transferable?
How do I handle this situation? Should I let it go?