Car Conversation

So I am driving in the car with the kids today, and Ben is talking up a storm (as usual).  Then there's a brief, uncommon pause, and:

Benjamin : I smell a poopy diaper!
Daddy : Penelope, do you have a poop?
Penelope : No.
Benjamin : I can smell it!
Daddy : Penelope, are you sure?  Do you have a poopy diaper?
Penelope : No!  No poopy! I don't have poopy diaper!

There's a pause, while I sample the air in the car.

Daddy : Ben, I don't smell anything.  Are you sure its poop?  Are you smelling something else maybe?  Did someone pass gas?
Benjamin : Well....

... and then I can hear Ben making an odd noise.. it sounds like he's hyperventilating, and I am not sure what's wrong. I glance back for a second to see that he's really breathing weird.. out through his mouth, in through his nose, really rapidly.

Daddy : Ben, are you ok?
Benjamin : Yeah.  Its not poopy.  Its my stinky breath.
Daddy : Oh. Ok.  Good. (Good?)
Benjamin : Yeah... sometimes when I play Wii it makes my breath stinky.

Video games get blamed for a lot of things, but I think this is a first.