That's pretty much how I see it, too. A relationship would feel very weird. Not that one can plan love or anything, but I mean, as a general rule, it does sound like a pretty bad idea. But the fun-part should be OK, yeah?
Reason I ask is that I usually don't roll like this (them being so young), and when it occured to me that she's 1 year younger than my youngest sister, I became a little ...
But she's a cool gal, and quite mature for her age.