He was pretty zoned in and his concentration was written all over his face. I was watching from the sidelines when he got a look of horror on his face, and immediately stopped biking.
He dismounted and walked over to me with a look of concern. "Mom" he said, "I think I pooped my pants". I responded with assurance that accidents happen and that it wasn't a big deal.
After walking a few steps towards the house he stopped and said (as if confirming a diagnosis) "Nope. Nope. Wait...you know what mom? I think it was just a slimy fart".
I couldn't make this stuff up if I tried.