We see six very short flashback scenes of David and Gail making love (from few frames to 2 sec) that clearly show what is happening but we see only their faces, or back, in one scene we see Gail sitting in David lap facing him, but he's wearing trousers.
While in the infirmary for medical reasons, Alicia Hamelin (4) hears crying from the next room that was the sleeping quarters for the boys. She gets up to investigate and sees a priest over a boy that she says was "naked and bent over". All we saw was the back of the priest pressed up against the back of a boy. The priest sees Alicia and tells her to leave and close the door.