Oh boy Jill!
Stop worrying right this second! Your son is going to have the time of his life! My nephew went on his first Disney cruise when he was 15 years old. He was grumpy (no pun intended), didn't think a Disney cruise would be "cool", and thought he would be bored. He's 23 years old now, and has been going on Disney cruises since he was 15!
Kids ages 14-17 go to the youth club,
Vibe. It's amazing! He'll have made friends by dinner time, and how lucky is he that he'll have his sister to hang out with until then? The youth counselors are trained to make the kids feel welcome, and they've got a talent to get them all to mingle. My nephew is still in contact with kids that he met years ago from other countries around the globe! My sister told me that she only saw him at dinner (she forced him) and when he went to sleep. So no worries! He won't have time to be bored. There are tons of
activities and other teens for him to hang out with.
I hope this helps Jill. Please let me know if there is anything else I can answer for you. Have a magical trip!