Robert was a newly arrived recruit of the French Foreign Legion to outpost 198 in the middle of the Saharan desert. The post consisted of a regiment of volunteers from all over the world sent to guard basically a crossroads.
After a day or two Robert noticed that there weren't any women around.
After a week, it started to bother him a little, being a healthy 24 year old with a normal sex drive.
After about three weeks, he started to get desperate, and asked one of the older grizzled veterans what he did to relieve the pressure. The grizzled veteran winked and said "follow me". The Vet led Robert to a shack in the corner of the compound. Inside the shack was a large barrel with a hole in the side.
"When you're feeling a bit congested, just stick your tallywacker in the hole there, and you'll soon be relieved!" The vet explained.
Robert pondered that for a few days, but curiosity got the best of him, and finally one night he left his tent and entered the shack. Closing the door behind him, he found himself in near total darkness. He unzipped his pants, and stuck his semi-erect cock into the hole in the barrel.
Suddenly, his wang was enveloped by the warmest, wettest softest sensation he's ever felt. Soon he was blasting his cum deep inside of whatever it was draining him dry. Shuddering with delight, he felt the last few drops of goo get siphoned off his cock, and disengage.
Robert was a changed man. Every night it became his ritual to go visit that shack. This went on for a few weeks, until one night, he went to the shack as usual, whipped out his rock hard dick, stuck it in the hole, and....nothing. Bewildered, he withdrew his cock, then stuck it back in. Still nothing.
He pulled out, zipped up, and went to go find the old vet to ask what was wrong.
The vet replied "Oh, sorry, no one told you, it's your week to take a turn in the barrel".