You've apparently never seen his famous advice on choosing older women as mistresses, have you? :)
Benjamin Franklin had a son out of wedlock - William Franklin. He was raised by Benjamin and his commonlaw wife Deborah. Benjamin couldn't marry Deborah because *she* was already married!! And William's son Temple fathered a child out of wedlock by his stepmother's younger sister. Jefferson had Sally Hemmings (who was the half sister of Jefferson's wife Martha - they shared a father.)
Check out the history they didn't teach you in school, lol. It may not have been in Paris but the Founding Fathers weren't necessarily into marital fidelity and monogamy.