Zayn's not stupid, he may only be 13, but he's not stupid. He knows that he's... developed, more than most 'boys' his age. So why not take advantage of it.
He knows what he does to plenty of guys when he shaves his legs and where's those pretty clothes. Batting his eyes and biting his lip when he asks for something. Or when he gets grow men to call him princess, or cupcake, or even babylove. Playing innocent never hurt anyone.
So maybe, just maybe, it sends a 22 year old Niall over the edge. A Niall who wants to be the only one to call Zayn "my little babylove."
Copy my story and I'll cut you.