This was her punishment, to leave her wanting him and him not giving her what she desired. What he had done was merely intoxicate her. When he kissed he, he infused a toxin into her blood. But he wasn't making her act this way. The toxin only brought to surface your ebbed sexual desires, it empowered the feeling of lust within the person. Lust is one of the seven sins intrinsic in human beings and Wu possessed the power to enhance those sins at will.
He was about to walk away upon accomplishment of his aimed task, yet what she said next stopped him dead in his tracks.
"I'll have someone else do it then-" Next thing she knew, her back was slammed against the wall, his body was pressed into hers and his hands were slammed besides her head, capturing her little frame within his armed fortress.