A/N: We've done something like this before, but I wanted to take it a different way.
Blaine punched hard, slamming his fists into the material and letting out little snorts as his eyes narrowed.
Kurt watched on, eyes wide.
"I'm not sure I like the idea of violence."
"It's not violence. It's...release."
"I can give you release..." Kurt said softly, adjusting the straps on his fists. "You don't have to resort to... punching things for release."
"Mm..." he punched the bag again, growling a little.
"Blaine..."
Blaine wiped his brow, sighing at Kurt. "You give me different release. Better, and different."
"But I mean...if you get angry...if you hurt someone because of this."
"No, no, no...babe, this is teaching me not to punch someone in the face."
Kurt sighed, sitting at one of the benches. "I don't understand."
Blaine loosened his shoulders, pulling off his gloves. "I get rid of the angry by punching."
"I get rid of the angry by running." Kurt said softly, and Blaine laughed.
"What's wrong?" Blaine finally asked, dropping his hands completely and turning to pay full attention to Kurt.
"I don't like violence."
"Violence is hurting someone. This is hurting something."
Kurt shrugged. "I don't want you to stop...pummelling the bag."
Blaine sighed. "Then why are you here?"
"Because..."
"I'm not trying to kick you out or anything...but I am trying to work out here."
Kurt shrugged. "I like to watch you anyway."
Blaine laughed. "You have far too many double standards."
Kurt frowned and pouted.
"You're cute. Want to be my sparring partner?"
Kurt frowned. "You mean your punching bag?"
"No..." Blaine went back to his punching bag, punching lightly. "Sparring partner. It's non-contact punching and kicking. Like self-defence."
"...pretend fighting?" Kurt raised an eyebrow.
Blaine sighed.
"Let's go with that."