A few days ago, I made a huge mistake that will probably ruin my relationship with my fiancée. If she finds out about it, and that mistake was that I slept with one of her friends. Since then I have been feeling really guilty about what I have done and I've been thinking about just coming clean and telling her that I've cheated on her with one of her friends. But at the same time I've been that maybe it would be better not to tell her that about it because of how much it would hurt her. So I came here to get some advice on what would be the better thing to do.