When Charlie arrives back home, he tells the prostitutes, "Thanks for the ride, girls, and for bringing me home." Previously, in s2e14, he made a very similar joke after coming home, saying "Thanks for the ride, Sally. And for getting me home, too." In both cases, the women are not seen or heard, while Charlie appears drunk.
Alan telling Charlie that he and Judith did not technically have sex that night is a veiled reference to the infamous quote by former President Bill Clinton, when he stated, "I did not have sexual relations with that woman", in reference to the Monica Lewinsky scandal.
The episode's title refers to Herb's statement to Charlie, in which he confuses the model train scale "H.O." with the word "ho".
Episode title spoken by Herb, to Charlie.
Charlie Sheen and Ryan Stiles (Dr. Herb Melnick) co-starred in "Hot Shots!" (1991) and "Hot Shots! Part Deux" (1993).