[M4F] Siblings have to share a room at Christmas time

We are siblings and we have to be together in your room during the festive period so that visiting family can use my room, How long can we spend together surrounded by family while not able to masturbate or have sex with anyone as we are trapped at home for the Christmas period? And will we be caught by the rest of the family?

I am 18+ and all participants and characters must be 18+