Credit: Twitter

Sure, Castle is all about investigating murders, but that doesn’t mean the cast can’t have fun while doing it!

Today, stars Stana Katic and Nathan Fillion were spotted goofing off with actor Morgan Peter Brown on the Castle set. Since Morgan tweeted several photos from the set, we think he’s probably going to have a guest role on the show sometime soon.

Credit: Twitter

Some of his previous credits including a guest spot on How I Met Your Mother and on the new TBS show Wedding Band. 

Morgan first tweeted, “On the set of ‘Castle’ yesterday with Captain @NathanFillion,” including this sexy shot of our favorite mystery writer. He then shared a silly photo with Stana saying, “With Kate Beckett/Blowfish @Stana_Katic. Serious business.” 

Fine, we’ll admit it — we’re jealous. Sigh, maybe one day we’ll pal around with the Castle stars too! 

What do you think of these adorable behind-the-scenes pics? Weigh in below!