Singer Jason Mraz proposed to girlfriend Tristan Prettyman on Christmas Eve, but they made a solid vow to each other: not to get married until gay marriage is legal. “We both feel that in our engagement, we have a union that’s really special and can’t be broken. It’s a sacred bond,” Mraz told Us Weekly. “The wedding would be nice for our family, our friends, our community – our moms especially – and so it puts us in the fight.”