As if anyone in this chat doesn’t have some secret that would screw up their life if people found out. It could be theft, physical or emotional abuse, anything against the norm. But we have no problem chastising actions of others without considering our own. So, it is to be assumed that if you were in a great relationship and your “other” made a mistake of having sex with an ex one time, but then realized it was a terrible mistake and the life alternating affect it would have if you found out, you would rather have your perfect relationship end by being told the truth about a single indiscretion. The world is filled with mistakes we all make. This is no habitual cheater. Taking them at their word they didn’t do it before and won’t do it again. Telling on yourself out of guilt, ruining a great relationship when there’s no way of your partner knowing about one indiscretion, means you have a child’s view of what’s right and what’s wrong. Grow up.