Amon is surprised to hear the language Rea is using. If anyone looked at her, they would think she was an innocent, untainted girl, but Rea no longer fits this description.
As Amon came into her life, he slowly turned Rea from an innocent girl to someone who dreams of being roughed up by him.
A girl with daddy issues, someone who has been deprived of fatherly love and guidance, now fantasizes about Amon being her daddy and doing naughty things to her.
"You are doing it wrong," Amon says, which startles Rea. She almost falls off her chair, but Amon presses down on her shoulder and stops her fall.
Rea realizes that it's Amon and immediately gets embarrassed by her position.
"Daddy..." she says meekly and looks down, unable to meet his eyes. Amon bends down a little, puts his hand below her chin, and lifts her head.
"No need to feel shy in front of me," Amon says and bends down a little more and meets her lips with his.