In the episode "A League of Their Own", Cliff meets Marc St. James in a photoshoot that Wilhelmina made him supervise, and invites him to watch the film Psycho with him. After he learns that Marc cancelled their date (which he didn't think it was at the time) to go out with an underwear model, he leaves the MODE building after telling Marc that he thought there was more to him. Near the end of the episode, however, they ended up spending their night watching Psycho.
In "Something Wicked This Way Comes", Cliff thinks that Marc doesn't want to be seen with him when he comes to visit, and learns that it is the case in a later conversation with Marc and Amanda where he is introduced as a friend. He breaks up with Marc, stating that he "has too much respect for himself to put up with this". When Marc learns that he will get a +1 to the Slater-Meade wedding, he calls Cliff to patch things up.
In the 7th episode of season 2, "A Nice Day for a Posh Wedding", Cliff and Marc are back together again. Marc being too preoccupied with the wedding, agrees to Cliff wearing his brown blazer with ketchup stains. At the wedding, Marc feels panic over how Cliff will look when he enters through the doors (Amanda "calms" him by saying "sweetie, relax. He can't fit through those doors") but is very pleased when Cliff appears in a suit, clean shaven and with a much neater appearance. Cliff is later talking to a model he used to work with, igniting Marc's jealousy and causing Marc to break up with Cliff. They got back together moments later (after Marc got some advice from Amanda) and sat together during the entire wedding.
Marc and Cliff, while recently going to rent movies for a date, discovered that Wilhelmina's first choice for a surrogate mother, her manicurist named Brandy, was actually a Dominatrix/porn star, thus averting disaster with her plot to give birth to an heir to the Meade Empire.