Ahhh.. like father, like son. I think the hands behind the head gene is dominant. It's like Trevor can't help to do it.. he is just very very good at lounging or as Daddy puts it : "Maxin' and relaxin'. "
You don't really need a reason to send water balloons flying 350 ft. down the street with a slingshot, but I would recommend watching adult men get excited and belly laugh about it any time you can arrange it.