My daughter has a boyfriend who lives with a gay man who lovingly stares at him. Should she get married?

The boyfriend is 30, the gay is 26, my child is 21. The boyriend bought a house suppossedly to get married but the gay man is moving in with him. There are no plans for him to move away as he cooks and cleans house; he is a teacher. I don't have anything against gays but certainly one in my baby's honeymoon would sadden me. There is nothing I can do and I don't know how this is going to work out. Am I being irrational?