My uncle told me:
They lived in the summer at a sports camp near the sea. And one night they wanted adult entertainment (and they were then 15-16 years old). In general, they got somewhere a bottle of wine and went to the city beach, where no one is late at night and where they actually began to devote themselves to alcoholic excesses and swimming - naturally naked.
Alcohol affected the young organisms decisively and unexpectedly – when the bottle of wine ended, they fell asleep.
And when the uncle woke up, he first looked at his genital organ. morning erection), then on the same naked comrades, and then on several hundred holidayers of the Crimean resort!)