In the previous episode, Gary is celebrating his 40th birthday. In this episode, there is a flashback to 24 years ago when Catherine is being born, and Gary is Selina's bag man even then - but he would have been 16 at that time.
Matt Walsh (Mike McLintock), Sam Richardson (Richard Splett), and Randall Park (Danny Chung) also worked together on Office Christmas Party (2016) as Ezra, Joel & Fred respectively.
Emily Rutherfurd previously starred in "The New Adventures of Old Christine" with Julia Louis-Dreyfus.