What do you do when your kid rejects a friend?

There comes an uncomfortable turning point in the parent/child relationship when the child realizes that he has opinions about whom he wants to befriend, and that his opinions do not necessarily jibe with his parents’. Usually, or at least over here in New Jersey (in our house, to be precise), this takes the form of rejecting previously acceptable friends. (We haven’t yet encountered the problem of Henry bringing home a shady character. So few preschoolers drink or smoke, these days.)
To some extent, of course, these children of ours have had opinions about things right from the beginning. For instance:
Parent: “Hey, newborn. We think you should go to sleep now.”
Newborn: “No.”
This continues as they develop:
Baby: “I’m hungry.”
Parent: “I fed you ten minutes ago.”
Baby: “Let me repeat myself, except louder.”
But when it comes to friendships, babies and toddlers don’t really have an emotional investment. Thus, they happily allow you to tote them around to playdates that are more for your benefit than theirs.
Until.
Until the day comes when your child notices the kid playing next to him, and decides that this friend you’ve chosen for him is not the kind of friend he wishes to have. The day that your child thinks, hmm, she’s getting a lot out of this playdate, with her tea-drinking and chortling over there with her buddy, and meanwhile I’m stuck with a mouth-breather who doesn’t know a Lego from a Lincoln Log.
(No offense to mouth-breathers, whom we count among our friends. Most of the children we know are incapable of getting any air through their perpetually clogged nasal passages. But I digress.)
This has been happening increasingly over here, which is why I chose to write about it. It’s Shameless Self-Interest Day, didn’t you know? Please make a note in your calendars. Anyway, yes, Henry has been refusing to see certain friends and classmates in his free time, and I’m conflicted about how to deal with it. On the one hand, he has the right to be friends with whomever he wishes (within reason—I cannot and will not invite Batman over); on the other hand, I want him to be tolerant and kind; on the third hand, sometimes he has to suck it up, because we want to see our friends, too.
I try not to make too much of it when Henry decides to nix a playdate. Usually these rejections are meaningless or short-lived. Sometimes there’s a simple reason he doesn’t want to set foot in the kid’s house, like the other kid is an enthusiastic hugger and Henry would rather enjoy a more low-key greeting. One phone call can ensure that she keeps her mitts off my boy. Other times he’s just being contrary, or a jerk. These moods can shift within minutes, so I move on to another topic, and usually the next time the playdate idea comes up, he’s more than agreeable.
Sometimes, though, sometimes he just refuses to hang out with the other kid, just plain won’t go. And then I’m put in the position of having to tell the parent. Recently I had to tell a woman I was really hoping to befriend that my child wouldn’t hang out with her kid. Not just one time—ever. He would never have a playdate with this boy. Why? He wouldn’t say. He just didn’t feel like it. There were many discussions. Henry stood firm. There were other friends, he said, he wanted to make time for. That’s a feeling, frankly, I can understand. What could I say? I had to try and make light of it to the mother.Ha ha! Crazy kids! With their, um, rejecting of your beloved!
I haven’t heard from her since. Oops.
I didn’t see any evidence that he was being cruel or superficial in his decision not to make this particular friend (the other child has plenty of friends, and is frankly a little bit cooler than my kid, shh, don’t tell him I said so) but still, I would have preferred that he had given the boy a chance. I want him to learn to be kind and generous, especially to someone who extends an invitation of friendship. But he is only five, after all. Lecturing him on the importance of kindness and generosity, at this stage, wouldn’t make an impact. So meanwhile Scott and I try our best to be relatively okay role models, and hope he gets the message, eventually. But if he had rejected a kid who really needed a friend, what would we have done then? Probably resorted to lectures. And threats. I might need a better plan.
So I turn to you, my Internet family: have your kids rejected another, and how did you deal with it? Did you put your foot down? Is it your kid’s business and your kid’s business alone whom they befriend?