I fucked this girl that i work with after a work function, we had drinks at a bar with other coworkers and she needed a ride back home so i drove her. She invited me up and things happened from there. We're in a small office of 20ish people, she doesnt directly report to me (diff dept) but i am in a supervisory position. In the morning i told her it was fun but we were drunk and this was really a one time thing, I asked her to keep it between us. She was cool about it and agreed.

Fast forward a month and of course she couldn't keep her mouth shut lol. Friend coworker comes up to me and says "Tell me a secret" i play dumb but still get him to tell me everything he knew, I deny it.

Im not butthurt about it because I have no expectations for people on keeping their word, but Im wondering if I should let my boss know what happened? Part of me thinks it isnt anyones business what i do outside of work, and there arent any problems being caused by it so no big deal, just ignore it. The other part of me thinks that being reactive about the situation makes me look dishonest and forces me into a bad frame.