Omg Jamie is pinning down Jack aksjdjalkjsdfhlasdkjfhalskjdfha~!
I feel like Jack is thoughts like: "No! I can't do this- This is Jamie, first kid to ever see me and best bud and bro! And way younger than me!" and other such reasonable, valid reasoning as to why he-should-not-do-this,
That's all derailed by one single thought that a large part of him thinks- Namely this: "Oh no, he's hot!"
Which is why he's totally letting Jamie pin him down like that, because Jack could totally push him off if he wanted to, but he doesn't so he won't. Lol. xD
I can imagine what happened :3 -Jack flies into Jamie's room- Jack: hmm...he didn't tuck in properly... -flies over- Jack: hm? ...?! -Jamie grabs him and pins him to the bed- Jamie: Finally, I can catch you...(taken from your pic) Jack: Jami-?! -smooch- and there you have it my imagination~