I agree... I get the feeling that she's owned by someone else. But I have a hard time believing that she likes the singer because she never even tries to leave the other guy. If she wanted away, we'd see scenes of her being dragged back to the guy. Instead, we repeatedly see scenes of her jumping back onto his lap.
I think she's a drug addict. Apples have always stood for temptation, and the way he just gives those things out makes me believe that she's hooked on the apples. She even looks strung out.
So, to summarize, whatever is going on, the girl is obviously out of his reach. Try as he might, he will never have her, so he leaves.
On a separate note, the lead singer kind of looks like some actor. I'm thinking Matt Damon or the guy who played Robin in Batman - whatever his name is. Anyone else see any resemblence in the guy?