Now that Zane is intoxicated, he became less aware of his surroundings and this was the perfect opportunity for Amon to make his move.
He could, of course, use his all-powerful power to just make Zane ignore his girl, but that would be no fun. He wanted the thrill of fooling around with someone's girl while they were still a little aware of their surrounding.
Zane might be intoxicated, but if Amon blatantly fools around with his girl, he will definitely notice it.
Zane is so drunk that he hasn't even noticed that Amon is sitting right next to his girl now. Lia, on the other hand, is very aware of Amon's presence right next to her and her body is tense because of it.
Amon's sheer size and presence overwhelm her, even though he is not touching her. She turns her head and looks at Amon and gives him a smile.
Amon looks at her and smiles back.
He then makes his move. He puts his hand on her exposed, soft thigh. Lia is taken aback and her body stiffens up at Amon's sudden action.