Hazelmary and Peter Bull refused to let civil partners Steven Preddy and Martyn Hall stay in a double room at Chymorvah House in Marazion in Cornwall in 2008.
The couple, who had already lost cases at Bristol County Court and the Court of Appeal, said they were "saddened".
Mr and Mrs Bull have said they regard any sex outside marriage as a "sin".
I'm glad our Supreme Court upheld the complaint by the couple denied their stay. It cements even further the notion that a person's religious belief dictates only how they behave - not how they should expect others to behave.