Francois is shown and heard to be powerfully and vigorously "having at it" with Helene in the wide-angle shots near the beginning of the film, yet the interspersed close-up shots show him just doing it slowly and somewhat lazily.
The curly-haired pedestrian in the light blue shirt and dark-blue jacket is seen to be strolling steadily towards Eric's position where he's letting the air out of Helene's bike-tire, yet even after Eric finishes inserting the grain of sand and replacing the dirt-cap, the pedestrian is only a few strides forward of where he was when Eric first started to unscrew the valve-cap sometime earlier; he should have covered at least a third-to-half the distance between himself and Eric in that amount of time.
Both Francois and Helene collapse sideways onto the dune grass in a semi-spooning position after their wild intercourse-session, yet a moment later, Helene is again in her previous squatting-on-all-fours "doggy style" position, with her head exhaustedly drooped down in front of her.
Francois's "little buddy" is shown to be clean, dry, and normally "springy 'n' spongy" just a few seconds after his vigorous intercourse with Helene; his "equipment" should still be messy-wet and limply-exhausted after having just been thrusting inside of her moments earlier, especially since Helene's accompanying "climax-screams" imply that he'd majorly "emptied himself", as well. Obviously the film-makers either filmed the "oral-sex afterglow" scene prior to the intercourse scene instead of afterwards, or else they waited a while till the dude had washed himself off and rested up to restore some of his "fullness" before they started to film the oral-sex scene.
Corinne in the cradle is clearly not squalling, even though the sound effect of a baby's tearful screaming is heard.
Miss Curly-Wig is heard to be giving loud and copious "ecstasy moans and gasps" while Francois is "doing it" with her, yet her mouth is mostly closed during the intercourse; she is clearly not saying anything or doing any deep heavy "wide-open-mouthed" breathing.
Helene's joyful "ecstasy murmurs" can be heard even during periods when she and Eric are kissing.
Eric had been careful to stop his bike's motor when approaching Helene's house the first time, yet when he returns the second time, he putters all the way up to the gate under power; he would surely have not wanted Helene to hear him that time, either, since he was again there to discretely spy on her and plan how to approach her romantically.