I still can't believe people were defending this. Yes I do realize most practical jokes and pranks are questionable in their morality, but I feel this is one of those lines you should never cross with your parents. What happens if some of them actually enjoyed it and they end up in an incestuous relationship in the future? Wouldn't the school bare some responsibility for future child sexual abuse?
The point is this is sexual. As has been mentioned above, you wouldn't want to see your girlfriend kissing someone else in this way, because it is sexual. And why are we encouraging sexual behavior in kids anyways? No wonder the U.S. has such a high teenage pregnancy rate among developed nations. I know when I start kissing, I get hard, and I do want to have sex. I can't exactly stop at just kissing. And why are we also encouraging public displays of a sexual nature? I hate seeing people kiss in public. Yes I get jealous. But unless the woman is going to kiss me too, she shouldn't do it. I don't want to see that crap unless they are going to include me in it.