A French man allegedly sexually abused a sleeping woman he sat next to in the first-class cabin of a Miami-bound flight — and returned to leave her a creepy note, according to court records. Guillaume Sebastien Roger Mattler, 48, faces a count of abusive sexual contact for the disturbing incident that unfolded Tuesday on Swiss International Air Lines Flight LX64, according to a federal criminal complaint obtained by The Post. Guillaume Sebastien Roger Mattler, 48, allegedly sexually abused a woman he sat next to in the first-class cabin of a Miami-bound flight. Corbis via Getty Images Mattler and a 29-year-old woman, whom he did not know, were “seated next to each other in the first class cabin” on their way to the Sunshine State from Zurich, the complaint said. The woman dozed off during the international flight when two other passengers witnessed the stomach-turning behavior.…