Drunken confession, do you keep it, or expose it?

Let’s say for instance you know of a couple that has a strained marriage at best, during a function (party, mixer, BBQ, etc.) after the female half of the couple has had a few too many she drops a bomb on you that you did not care to know; she was having affairs. Not only that as much as you try to cleave yourself from the conversation by moseying off, even tacitly telling her it is none of your business, she insist on telling you how great the sex was and how the ”lovers” were so much better than her husband. If you know him but he is not a real close friend would you tell him, or stuff it in your mental round file? Would you share it with your partner after you left the event or got back home? If she did not remember she blabbed it to you, would you let her know all she said to you?