We are getting ready to go on our third cruise. Son is 15 this year, 14 last year and was 11 on first cruise. There are TONS of things to do. First cruise he was too young for teen stuff so I'll skip that except to say that we all had a blast at Studio Sea.
Next cruise he hung out a lot at ESPN and a lot with teen group in Common Grounds. It helped that we were seated with a family who had a son his age. They hung out a bit and he also met other kids at Common Grounds. The teen group had scavenger hunts, "gotcha" games, filmed a skit, midnight swim parties, dances, etc. The counselors tried to make sure everyone was included and felt welcome. On
Castaway Cay there is a teen beach - we didn't see the kids all day! On the Magic Western there is a teen cruise in Cozumel.
I understand from the boards that the nightclub venues are now open to families until 9. I'm looking forward to that - last year my husband and I laughed so hard at some of the stuff that we cried!
Your son may be thinking it is all Mickey and Minnie. While there is plenty of that for the little ones, there are a lot of fun things for others too!