This is based off aa popular headcanon that sometimes when Cole gets his scar wet it really stings from being a ghost, it's not confirmed canon :)

You and Cole were in the kitchen togther, sat at the table, meerly just talking and joking togther. You took a sip from your glass of water, and on the way to put it back down your hand slipped slightly, and a few droplets of water left the glass and onto the table. Well, apparently one of them didn't go onto the table, and it came into contact with Cole's green scar that reached from his forehead to just under his right eye

"A-ah!" He exclaimed as quietly as he could, his hand instinctively going to where the water hit him.