 " Galentine 's Day " was written by series co @-@ creator Michael Schur and directed by Ken <unk> . The episode featured a guest appearance by John Larroquette as Frank Beckerson , the long @-@ lost love of Leslie 's mother , Marlene Knope . When Parks and Recreation co @-@ creator Greg Daniels announced the casting in January 2010 , he described Larroquette 's character as " He 's the one who got away . " " Galentine 's Day " also included an appearance by Pamela Reed , who has played Marlene Knope in several episodes , and the last of a string of slated guest appearances by Justin Theroux as Justin Anderson , a love interest for Leslie . The episode marked the return of Andy 's band , " Mouse Rat " , which was previously featured in the first season finale " Rock Show " . His bandmates are played by Mark Rivers ( drums ) , Andrew <unk> ( guitar ) and Alan Yang ( bass ) , the latter of whom serves as a screenwriter for Parks and Recreation . 
