A boy (Pétur Björn Jónsson, 9) coerces a younger girl (Steinunn Þórhallsdóttir, 7) to play 'show-me' (in exchange for trying his bike). They then go to a recluted place, where the girl pulls down her panties (seen from behind, obscured by her skirt) and lifts up the front of her skirt, showing the boy 'her privates'.
Dieter (Dieter Hallervorden Jr., 5) is undressed by his dad and runs around nude when he's trying to avoid getting a shower. He ends up standing in the bath being washed. This is all part ot the title sequence.