Soren has a pretty good sense of humor; it's easy to make him laugh. But sometimes I suspect that he is just humoring us.
"Ah yes, once again we're doing that peek-a-boo thing that you guys seem to enjoy so much. Hahaha, very humorous indeed. Let me guess--you're going to pull that blanket back down off your face again, right? Yup, there you go. Haha, good one."