Ross and Rachel, arguably the most well-known couple from "Friends", encounter several difficulties in their relationship which is characterized by its on-again/off-again nature. However, the primary reason for their first major breakup takes place in Season 3, and it revolves around the concept of “we were on a break.” The story starts when Ross becomes increasingly jealous of Rachel’s coworker, Mark, and suspects there might be something more than just professional interaction between them. This leads to a series of arguments between Ross and Rachel, and culminates in the episode “The One Where Ross and Rachel Take A Break” where, after a big fight, Rachel suggests that they should take a break from their relationship. Ross, upset and confused, ends up sleeping with Chloe, the girl from the Xerox place, a decision he immediately regrets the next morning. However, Ross's one-night stand is divulged to Rachel, due in large part to the meddling of Gunther, and leads to the infamous "we were on a break" argument, and ultimately their first significant breakup. It is worth noting, the phrase "we were on a break" becomes a recurrent joke throughout the series. Ross invariably stands by his belief that what he did was not wrong since he and Rachel were on a break when the incident occurred, while Rachel maintans that it was indeed a form of cheating. In the grand scheme of the show, this breakup is significant as it punctuates their relationship throughout the entire series and shapes many of the situations and decisions to come as the seasons continue.