I believe he did babysit them so they could go to the ball! So they know him already. The kids love magic so they probably would have had fun with that, and then shown him the things they can do -- like fly and turn into wolves and stuff. Conner probably tried to make himself HUGE AND MONSTER like, cause he's been practicing.
Snow would have asked all kinds of questions like what she did back home and how she's handling this dimension and the general run of get-to-know you stuff.