Frank Beckerson was in love with Leslie Knope's mother Marlene when she was 18 years old. He saved her when he was working as a lifeguard in 1968 and they had an affair for two weeks before never seeing each other again because her parents objected. He suffers from panic attacks and has had four heart attacks.
After telling Justin Anderson of the story, Leslie and he go out to find Frank and reunite him and Marlene in the episode "Galentine's Day". Frank, however, mistakes Leslie for Marlene at first and tries to kiss her. He then awkwardly shows her naked photos of her mother. On the car ride to the senior citizen Valentine's Day Dance, he throws up in Leslie's purse at the thought of meeting Marlene. At first, Marlene is excited to see Frank, but after he announces he got a job at a grocery store right out of college and he is completely unemployed currently, she isn't as interested. He suggests they pick up where they left off, but Marlene rejects him.