A housekeeper says to Armanda about Vincent's behavior:
Housekeeper: You know Vincent actually did his ungodly act on a Sunday? That's not the half of it. I saw him that Day. I was on my way to church. Laughing and joking with those Sacretain boys, drinking they were laughing at God, knowing what he was going to be doing on God's day.
What does "it" mean?