With all due respect, I think the lack of consideration shown in this thread is frightening.
This ignorance of the other’s situation is what turns people off of Catholicism. I have seen it far too many times. As Catholics, we are called to love these individuals with our whole being. Simply dismissing a friend who choose to disclose something personal such as this to you is beyond being a bad friend, it’s being a bad person.
Of course, you do not need to agree with this person. Someone mentioned it before - imagine the supreme witness you could give to our faith if you chose to handle the matter responsibly. Seagull, I know you don’t intend to come off as harmful, but by suggesting OP should break off a relationship because of a friend revealing a homosexual relationship by quoting Scripture isn’t right. Even if you wanted to take the road of repentance, responding to your friend’s confession as “you need to repent,” immediately, is going to distance the friend from the Church. You don’t understand the friend, what he’s been through, what his motivations are. Treating him like a brother of Christ doesn’t mean that you support how he chooses to live.