I had the chicken pox when I was 13, after my mom had tried and failed to expose me multiple times in childhood. And honestly, it was so miserable. I wouldn't wish that bad of a case on anyone, and thus will probably offer/encourage the vax if my kids haven't had it by that age. But that is just due to my own painful experience with it, which granted didn't give me any lasting side effects.
What does your teen think? Share the pros and cons and maybe he can decide.