A pleasure boat captain leased out his craft and services to an old and affluent man and his young,

A pleasure boat captain leased out his craft and services to an old and
affluent man and his young, very beautiful mistress. As misfortune would have
it, a storm wrecked the boat and stranded the three of them on some far away
island. The island was quite small and had only one tree which was often used
to look-out for passing ships.
The cramped quarters on the island made it very difficult for the captain to
pursue the young mistress. Even if the old man was on look out, there was no
cover for him to take her and have his way. She had already expressed her
desire to comply, but they could never get away from the view of the old man.
Finally, the captain gets an idea. The next time he is in the tree on look
out, he shouts down to the couple below, "Hey, stop having sex down there!" The
next day, he does the same thing. "Hey, stop having sex down there!", he says.
This continues for a couple of more days until the old man takes watch. As
soon as the old man is up the tree, the captain makes his move with the
mistress. The old guy sees what's going on below and thinks to himself, "Gee,
from up here, it does look like they're having sex."