sparkles

Noah likes to use his sleeve as a tissue when he's got a cold.  It looks like a snail has crawled up his arm.

Me:  Noah, this [sleeve] is not a snotty rag.
Noah:  I didn't do it as a [s]notty rag.
Me:  Then what's this?
Noah:  Mom, don't wipe it!  It sparkles.
Me:  Yeah, that's snot.