He's your classmate. There is a reason he hates you and stays away from you, because you are stupid according to him. And now picket your section in class. So after throwing away the trash you saw Killua and approached him.

"Don't touch me this time, you smell like trash. Clean your hands first, silly."

he lied in a disgusted tone while making a disgusted face too. He takes a step back away from you while covering his nose with his hand.