His eyes open wide, excitedly taking possession of the crayon to "do it myself."
That's a common phrase in a house with a preschooler! They're strong enough to do more & more things themselves, but this independence can also quickly endanger them. Like a child pulling a stool to the counter to grab something they shouldn't have (but want very badly). We've found simple art activities can allow us to quickly change gears with a minimum of tears and fuss.
Especially the hot glue and leaf rubbing plates below! Keep a stack of them in a basket with good drawing paper and beeswax block crayons for a great distraction during the hard moments and a joyful creative outlet during the better ones.