Maybe not brutalized exactly, but a pregnant woman is tied to a bed and force fed milk. When she refuses, milk is put into a needle to be injected into her belly.
Ending spoiler: the two adopted children get sent back to the orphanage for being violent, it's heavily implied that they escape in the night, follow the adoptive parents home and try to kill them and their baby
The two titular characters try to "baptize" their baby brother at 1:26:00 circa in a swimming pool, skip it to 1:27:04, the baby survives but it's very unnerving
The married couple do have sex at one point. We don't see them, we just hear them and see a bed in the background. Children sneak into the bedroom while it is happening, which is disturbing but the adults do not know they are there.