Castle star Nathan Fillion recently teased Castle and Beckett's coupling and what fans can expect to see in season 5. Fillion spoiled it will be a major adjustment and problems are sure to crop up after the 'honeymoon phase'.
"I think at first there's going to be a honeymoon phase where everything is great. They'll have to decide to whether to go public with their relationship or whether they're going to hide their relationship," Nathan teases. "I think Captain Gates, who already hates Castle, I don't think he's going to want her to know and she's going to find a reason why that's no good. So I think there's going to be an initial part where everything is fine, but I think rather quickly they're going to realize that just because these two characters are now together doesn't fundamentally change who they are. I think there are going to be a lot of problems now that we are just a lot closer, too. I think they are going to open a bit of a Pandora's Box. I think it's going to be tough going. I really do." He adds, "the most fun about playing [Castle] is the part about making him fail. When Castle has success, I will literally make him fall on his ass. I like doing that, I like that he's not perfect. Every time he's super cool I'll take him down a peg and I enjoy that."