On Monday, Castle fans got a shock to their system with the news series lead Stana Katic would be departing the show after this season. But while the official reasoning was claimed to be budgetary, Us Weekly is painting a different picture.Castle's Nathan Fillion finally addresses Stana Katic's exit."Stana Katic and Nathan Fillion completely despise each other," says a source in the story. Although their characters married in an episode in 2014, they're allegedly not on good terms when not working. "They will not speak when they are off set, and this has been going on for seasons now." The source adds, "This season, it got so out of hand they made Stana and Nathan go to couples counseling together." At times, Katic has been rumored to be in tears because of the tension on set.Unfortunately, there's no way of confirming the news without one of the actors speaking up, but it could explain why Katic was never even approached to renew her contact beyond the current season. Maybe she never had any intention to stay?