"Yes Mr. Spock?"
"What is this substance?"
"We call it Nutella, Spock."
"Ah." He takes a spoonful and licks it. "It has quite an agreeable flavour."
"Indeed it does."
Spock looks at the jar of Nutella, then up at McCoy, back down at the jar with a plan forming.
Spock takes another spoonful and looks at McCoy again, an evil look (or well, as evil a look can be on a Vulcan who doesn't change his expression) spreading across his face.
"Spock?" McCoy backs away from the man. "No. No, no, no. No, no you don't." Spock stalks toward him and smears the hazelnut spread across his face. "Why?" Spock licks him. "Oh..."