Megosztott hang

AITAH for saying we can't come to the Christmas eve party unless we can use the guest bedroom? Every year my mom hosts a family Christmas eve party. It is one of the most important events of the year to her and she’s let me know if I don’t show up it will impact the relationship. The problem is the sleeping situation is too difficult for my wife. For the last 5 years my wife and I have slept in the basement when we come visit. My wife has some medical issues that make it so she has to use the r