He saw the reaction, and mostly because he was indeed asking a favor (though also due to a small voice suggesting self preservation as a goal for the near future) he dropped the arm.
Her question made him feel odd, so he stuck his hands in his jeans pockets. "You're a girl, yeah," he nodded. "So. I was just wondering if you knew something about other girls, you know? Like, a good way to see if one likes a guy."
He didn't really want to ask anybody this question, but Red made him feel funny and the green guy wanted him to sing before he'd give any answers, and Rufio didn't know anybody else to ask. And he wanted to ask Megan, to see if she liked him, and if she'd want to do the "dating" thing that so many of the movies on the computer were about, because he wanted to hold her hand and stay very close to her every time he saw her. That, and when she wasn't around, he found himself thinking about her constantly, and spending a lot of time on his roof looking out for her flying through the sky.