The ships are very strict on this. They must stay in their own age group. 2 years ago we had all our grandchildren on the Conquest. We had a 14 yo girl and a 16 year old boy and they were not allowed in the same groups. They wanted to be together as they are cousins but had to mingle seperately. Nov 1 we go it again on the Valor. My grandaughter is now 16 and will be with the 15-17 age group and my grandson is 18 BUT he looks 14. So no 15-17 group for him and they do check their age! And looking 14 no 18 or 19 yo is going to give him the time of day unless she looks 13 or 14.
So I have feeling he will be bored. My 5 and 8 yo grandsons will also have to be in different groups. Luckily I have two 13yo grandaughters who will get to stay together.