Celia (Cristina Ramón, 14) is upset at the unrequited love of the priest, 'making-out' with a boy (~14) in the bedroom.
Celia removes her top, as the boy couldn't, exposing her breasts.
Mira comes to the barn knowing her stepfather is there and starts disrobing. His body obstructs the view under her shoulders. Then camera shows her from behind, whole back is exposed and we see a part of butt (might be body double). Next we return to the earlier point of view, as stepfather moves we see a side of her bare breast for a second. When he tries to give her clothes to dress she hugs him. Her mother suspects something’s going on and enters the barn in the moment when stepfather covers her bare back. She slaps her face first, then her (freshly divorced) husband.
Stepfather is in shower, Mira knowing he's there enters the bathroom. He seems not to be aware of her presence until he gets out of the shower and then Mira leaves.