Cheated on my wife with my son's babysitter?

(first of all, I'm actually 28 years old). my wife went to visit her parents and left me at home with my 3 year old son. I hired a babysitter (Mindy) since I was finishing up a project for work. after work, I made sure my son was safe, well fed, and asleep. the babysitter showed me that he was sound asleep. we then talked and watched Netflix together. I offered her some champagne and we drank together. then we had sex in the family room while my son slept.

what do I do? should I just hide this? a divorce may hurt my son. or is firing Mindy a good idea and leaving this behind?
Updates
+1 y
Mindy is 21 by the way
Cheated on my wife with my son's babysitter?
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