 " Hi , Infidelity " was written by John Enbom and directed by Michael Fields , marking Enbom 's twelfth writing credit and Fields 's sixth directing credit for the series . The episode features the second of three appearances by Laura San Giacomo as Harmony Chase . She and Enrico Colantoni had become friends when they co @-@ starred on the sitcom Just Shoot Me ! . They <unk> their friendship during production of " Charlie Don 't Surf " , San Giacomo 's first appearance , so they lobbied for more storylines together . Thomas was open to the possibility , saying , " I wouldn 't <unk> to go back to this , because I was really happy with how it played out . " 
