Jon Lovitz was one of the very first established celebrities to cameo on Friends, but he didn't reappear on the show until several years later. The actor's first appearance occurred in Friends season 1 as Steve. Lovitz later reprised his role eight years later, the longest span of a returning character in the series, even though there were plenty of celebrity cameos during that time.
Over the show's decade-long run, Friends was known for its ample amount of guest stars. Almost 200 episodes aired between Lovitz's two appearances. In those years, a number of big names appeared on the series, including Bruce Willis, Sean Penn, Julia Roberts, George Clooney, Gabrielle Union, and Brad Pitt. The list truly goes on and on but a number of stars played more prominent roles than others. For example, Reese Witherspoon and Christina Applegate portrayed Rachel's younger sisters in the series. Lovitz's character might not be as memorable, but technically, his arc lasted nearly a decade.
Lovitz was first introduced as Steve in Friends season 1 in "The One With The Stoned Guy". Steve was one of Phoebe's massage clients who happened to be a restaurant owner looking to hire a new chef. Phoebe introduced him to Monica, and in the hopes of being hired, she invited Steve over to cook him a gourmet meal. Steve showed up stoned after smoking marijuana on the ride over. He started to act strange and Monica ended up dropping him off at the hospital after he tried to eat a kitchen magnet. Lovitz reprised his role as Steve in the Friends season 9 where it was implied that the character became a drug addict following his initial appearance.
Steve returned in the episode "The One With The Blind Dates", in which Phoebe set up a blind date between Steve and Rachel. Phoebe deliberately put Rachel in this situation so that her friend would hopefully get back together with Ross after having a poor dating experience. Steve revealed that his drug problem caused him to lose his restaurant and ended up selling silk t-shirts. He also shared that he lived with two other men and believed that he was infertile before he started to cry, horrifying Rachel.
Lovitz has spoken about his Friends cameos, explaining how he received the opportunity. In an interview (via City Pages), the actor shared that he was good friends with Lisa Kudrow's brother, David. As a friend of the Kudrow family, he kept up with Lisa's career. The actress asked Lovitz if he would do a guest spot on the first season of Friends before the series even became a hit. He agreed, especially because he previously starred with Courtney Cox in 1988, so he had connections to multiple cast members. Lovitz remained close with many of the Friends cast members, which was why it would have been easy to set up Steve's return in season 9.