 The episode was written by series co @-@ creator Michael Schur and directed by Ken Kwapis . " Galentine 's Day " featured a guest appearance by John Larroquette as Frank Beckerson , the long @-@ lost love of Marlene Griggs @-@ Knope , who was played by Pamela Reed . It also featured the last in a string of guest performances by Justin Theroux as Leslie 's love interest , Justin Anderson . 
 The episode was written by series co @-@ creator Michael Schur and directed by Ken Kwapis . " Galentine <a href='null_genetive' title='1'><mark>'s</mark></a>Day " featured a guest appearance by John Larroquette as Frank Beckerson , the long @-@ lost love of Marlene Griggs @-@ Knope , <a href='null_relcl' title='2'><mark>who</mark></a>was played by Pamela Reed . It also featured the last in a string of guest performances by Justin Theroux as Leslie <a href='null_genetive' title='3'><mark>'s</mark></a>love interest , Justin Anderson . 
Da episode was written by series co @-@ creator Michael Schur and directed by Ken Kwapis . " Galentine  Day " featured a guest appearance by John Larroquette as Frank Beckerson , tdalong @-@ lost luh of Marlene Griggs @-@ Knope , was played by Pamela Reed . It also featured the last in a string of guest performances by Justin Theroux as Leslie  love interest , Justin Anderson .