Youth (Kiss). 1913 Kuzma Sergeevich Petrov-Vodkin (1878-1939)

The picture has something of this: nude, people, shirtless, naked, son, man, body, swimmer, H2O, baby, water, thorax, swimming, reclining, shape.
Perhaps it’s a painting of two naked men on a beach, one of which is kneeling down and the other is holding his hand in his other’s other hand.