No, I don't think you let it out too much at all ♥ Jade does know when shit needs him to be serious. I would be more concerned about if he was getting REALLY SERIOUSLY PISSED OFF about things. :|a I've seen Jades like that too. Jade can also switch modes very quickly, which I think you do rather well.

All in all I think he's awesomely balanced, so keep doing what you're doing!