Truly a great picture, but I find it lacking in that we cannot see the girls' facial expression. Is it pain, or maybe pleasure? We do not know. Though this may have been the intent of the artist.
From what's been going on with the pics done by Sakura (naisyo.petit-fts.com), she's probly enjoying it a lot but tries not to show it being a smart girl who doesn't want to have a boyfriend before highschool. ^^