> Actually it looks pretty good, and since you were sparse with the actual window-opening description it more or less checks out (spoken with the experience of someone whose older brother legitimately used to have to climb two stories up and swing through a window to access our own house at times due to issues with busted security locks, so yeah XD) 

Phew, I almost went into this whole shpeal about Jason climbing up to a second story window in order to sneak into his room, but decided I'd probably make myself look like a butt.

> The only question is how quickly people will figure out he's gotten in and how hard Damian throws the batarang at him/and or attacks him with a broom.

Well, they probably already know he was dicking around in the backyard due to him taking his time. Whether or not they know it's him is up to you guys, though it seems unlikely anyone that wasn't around when Jason was Robin/died would be very knowledgeable as to what he looks like.