King of the Hill (1997)

S2E14 I Remember Mono

On Valentine's Day, Peggy discovers that Hank had been dishonest during their courtship. He claimed he was sidelined at home with a football injury for a week, but in reality, he contracted mono from kissing another girl. Determined to get to the bottom of the story, Peggy embarks on a quest to reveal the complete truth, leading her to confront some old memories.