What is this???

Okay so we're at church the other day and I was sitting next to Thomas on the bench and I was holding Ethan. At some point during the meeting I see Thomas taking his pointer finger and "wiping" something on the bench. I saw a little something on the bench afterwards. This was our conversation: Mommy: " was that a booger, Thomas?" Thomas: Just looking at mommy, with a "stupid" look on his face. Mommy: "Thomas, is this a booger?" Thomas: " No Mommy, it's a SNOT!" So of course I wiped it off the bench and asked him to tell me about his "booger" rather than wiping them on things.