The pool water was blue but the air was hot when the coach with a big cock like a log rushed in to teach each child individually. The first girl was wearing a thin bikini, her breasts swaying to the beat of the swim, he pulled close from behind, his hands slipped down to grope her wet pussy even though she hadn't gone deep into the water. "You swim like a dog, I'll show you," he whispered, his stiff cock rubbing against his buttocks. I blushed but moaned softly when my fingers hooked my pussy, the slimy water mixed with the lake water. He turned me over on my stomach on the buoy, licked my pussy from behind, my tongue wrapped around the swollen pear seeds, I jerked and contracted, my pussy contracted repeatedly. His cock popped out of his swim trunks, his head was big and shiny, he pressed directly into the doggy pussy underwater, thrusting hard, the water splashing with each click. I screamed in pain, my pussy squeezed my cock, he slapped my red buttocks and then accelerated, penetrating deep into the uterus, making me tremble and cum squirting into the lake. The second one stepped in, knelt down and sucked his cock under the water, swallowing hot sperm before being carried up to the wall of the lake by him, the doggy continued, his cock thrusting into the shaft causing his pussy to expand, moaning echoingly. The whole group of sisters were taught by him to "swim specially" one after another, licking each other's pussies and then doggying collectively, the teacher's cock took turns piercing painfully and with crazy pleasure, sperm splashed all over the milky pool.