One question and one comment.
1. After May gave Darren the present he tried to kiss her in gratitude. Why did she pull back? Was it a reflex when she obviously liked him (as she impulsively kissed him the scene before).
2. I think Darren liked May and probably felt sorry for her in the beginning but he wasn't attracted to her physically, in fact the best way to describe Darren would be as an unsuccessful gigolo. He seemed very interested on how much money May had to give him and as far as the sex (according to her drawings) it seemed that May serviced him with fellatio more then satisfied her as a lover. I'm not casting any morale judgement, just an observation.