Does he mean ditch? As in where you pick to do something else and leave your buddy behind?
If that is the case then yes, yes I have. It was more so peer pressure where my cousin wanted to hang out with me and my friend did, too. They didn't get along so I ditched my friend for my cousin. I still feel bad about it. =(
I have "dumped" friends when I was in my early to mid teens when they started getting into things of a not so legal nature, I am no angel but breaking into houses was not my style so yeah I "dumped" friends in the past.