he gives them more wine and they get caught with the wine on their breath and so thats how the parents start so suspect somethings going on.

so arnold and dudley go back to the molestors crib and eat boston creme pie and watch XXX cartoons! arnolds disturbed by the cartoon but dudley like what he sees

so the molestor than convinces dudley to play NEPTUNE king of the sea by making him get naked in the bath tub...........