We go on holidays to do nothing...............
DS loves this.
We sit on the balcony and read and he hangs in his room like a vampire using YouTube.
We hit the pool (100 meters away) once or twice a day for a dip and a mess around, sometimes he joins us, sometimes he doesn't.
We all head down to dinner and have pre dinner drinks, dinner and then head back to the apartment.
Generally he will join us on the balcony (inevitable screen in hand)
and shoot the breeze.
We pay for one or two dives, if he wants them.
We approach it as three adults on holidays, with only two providing the finance...
we have taken this approach since he hit sixteen and it works well.
DH and I work our balls off during the year and feel no need to be active on holidays, so fail to see why DS should not just chill as well.