Why Kanda calls Lavi a Rabbit

Lavi was wondering the halls, slowly making his way to nowhere in particular, when he heard voices coming from farther up the hall. No not the voices that make people think you're crazy but the voices of Allen and Lenalee. "My name is not that hard to say!" That had to come from Allen, Lavi mussed. He then decided to add his two cents into the conversation. "It's his way of proclaiming that your friends." Both exorcists jumped at the sudden sound of Lavi's voice. "Well he doesn't have to be so rude about it." Allen huffed. Lenalee giggled and Allen suddenly asked, "How did you get your nickname, Lavi?" Before Lavi could answer Bookman came out of nowhere and ninja kicked Lavi in the head. "Come Lavi, I have work for you to do." He headed towards the library, not even waiting for Lavi to catch up. With some grumblings about abusive old men, Lavi said goodbye towards his friends and headed after the Panda.

X X X

Some hours later Lavi headed towards the Cafeteria for some dinner. After ordering his food he sat down next to Allen with his spaghetti. He only got a few bites down before Allen brought up their earlier topic, "Hey Lavi! You never told us why BaKanda calls you a rabbit." Lavi froze as he tried to think of an answer. Luckily before he could start stuttering, Kanda came to his rescue (sorta). "I call him an Usagi because he fucking acts like one." He then sent a glare that would have sent any man to his knees in fright, at Lavi; who flinched and paled. "Usagi!" Lavi started glancing at the exit. "What's the matter Yu-chan?" He gave a girly shriek (not that he would ever admit it) when Kanda pulled out Mugen and took off with the samurai at his heels. The exorcist left behind just sweatdropped before continuing to fill his black hole of a stomach.

Extended:
At Kanda's Room

"I see you didn't tell him the real reason, Yu-chan." the red-head cooed at his lover. "Just shut up and fuck me!" was his irritated reply. So the rabbit did as rabbits do, he fucked Kanda like no tomorrow. Oh, no Kanda would never admit that Lavi was like Energizer bunny; long lasting energy. And how he knew that would be his little secret.