Well IMO the python isn't playing.  I don't feel they are "wired" that way.  What type of substrate do you have it in?  Does the snake have a proper hide box?  Stress can cause a whole bunch of silly things with snakes.  My initial thought was, what does it have stuck in it's pits or nostrils???

Did this behavior begin after or before the bad fall while the kids were handling the snake?

Now I am worried.  He has been doing this since the fall.  We have been letting him mostly alone (my kids are grounded).  Otherwise, he seems to be acting as he usually does and nothing has changed in his cage.  He is on Aspen bedding, has a hide, water bowl, heat pad, heat lamp, climbing log.  He is in his shed stage and is spending a lot of time in his hide (usual behavior for him).  I don't see anything in his pits or nostrils.  I offered him his usual rat three days ago and he refused - again nothing unusual during his shed.  He also seems to be occasionally "chewing".  By this I mean it looks like he is clenching his jaws and the muscles in his head are moving a bit kind of like when a person gets mad and clenches their teeth.  Do you have any ideas what may be going on?  I would love to take him to a vet but have no money left over after $2500 emergency surgery for my dog last month.  Help!

John does this, but he will stick his head in blow bubbles then pull out and repeat in 5 seconds... 

I have two adult balls that seem to love to spend the extra time in the water, usually right before a soak.  Considering the fact that both are otherwise healthy snakes and this only happens during a shed I just attribute it to them wanting a little extra water.  I have extra large bowls that they can get their whole bodies into in their cages and they just love em.  Corner style dish.  The clenching thing I have a question about though, is he "yawning" right after that?  If he's moving his mouth around a lot he just might be trying to break the scales around his face free.  I wouldn't worry too much at this point.  Seems that maybe this snake has just decided that he really likes to soak.  I would check temps though, if you haven't changed anything and are sure he doesn't have mites, the temps might be a little off and he might be trying to self regulate his temp.  Just my opinion though.  Otherwise, like you said, he's in a shed pattern so this just might be a new habit that he's doing, or perhaps he's been doing all along but wasn't really noticed until after the fall?