Kindergarten Peer Pressure

I'm a little shocked that Ryan is already dealing with peer pressure in Kindergarten. For the last few months, he's come home with situations that frustrated him at school and we've tried coaching him through what to do and say in the future.

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One particular friend seems to be quite manipulative. One minute, he's refusing to sit next to him at storytime and the next minute he wants to be BFF. On the first day of school, this boy told Ryan that they were best friends and, ever since, their little leader/follower relationship has blossomed. It's so confusing for Ryan, but what's worse is that Ryan's getting used to being treated this way. We've tried to teach him to walk away when this kid isn't being nice to him and to play with someone else, but the problem is that Ryan really wants to be this boy's friend. It breaks my heart hearing the things he says to him. Things like "If you don't give me the red scissors, I'm not going to be your friend anymore" and "Eat your dessert before your pretzels or I won't play with you at recess." Honestly, I'm not trying to guide Ryan away from this friendship, but instead I'm taking every possible opportunity to teach him how to respond with confidence and not be a pushover. The times that Ryan has followed through with our advice, sure enough, this boy did a complete 180 degree attitude adjustment and wanted to be BFF again.
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Even though I've seen some of the bad behaviors while aiding in Ryan's class, I decided to actually invite this boy over for Ryan's first little classmate play date. I picked the boys up today and within minutes of being home, I saw the kinds of things Ryan deals with in school every day. By the time his mom came to pick him up, I had a pool full of yard toys, I watched as Kaylin fell on her tailbone when this boy slammed her down on the teeter totter, I battled him about not going upstairs while the baby was sleeping at least a dozen times and I laid down the law about being mean to Kaylin, even stopping the friend from spanking her. There was a short stint in the middle of the play date when they were using their imaginations and destroying the backyard building a fort and again when they played hide and seek for a while.
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After dinner, there was so much to explain to Ryan that I didn't know where to start. I condensed the whole lecture into one of our house rules: Do what's right, even when others don't and even when no one is looking. I'm kind of glad he's battling this issue now so he'll have lots of practice doing what's right before he becomes a teenager. But seriously...Kindergarten? Doesn't that seem a bit early for peer pressure???