Stay cosy and cheeky in Kevin Jonas’ “I’m on My Wurst Behaviour” sweatshirt. It’s soft, festive, and made to make people smile. Shop yours today. Get ready for the holidays with the funny Kevin Jonas “I’m On My Wurst Behavior!” Sweatshirt, featured in A Very Jonas Christmas Movie. This soft, cozy crewneck is the perfect way for Jonas Brothers fans to celebrate the season with a laugh. Add this unique piece of Jonas merchandise to your collection!