I've recently read several Twilight reviews, where the series was defended pretty much solely because Bella and Edward abstain from pre-marital sex.
I've read the whole series. They were neither as good nor as bad as they're made out to be (the writing, that is), although I didn't find anything especially original about them. My only reason for reading them was to see for myself if the Bella-Edward relationship is really abusive, since that was the chief complaint I heard. I just want to make this clear: when someone pins you to a bed to stop you from seeing someone they don't approve of, you are being controlled, and it is a form of abuse. When someone sabotages your car to prevent your free movement around town, you are being controlled, and it is a form of abuse. It doesn't matter if it's 'for your own good'. Abusers nearly always have reasons for their actions, and 'for your own good' is a pretty popular one.
Abstinence is great, and I'm all for encouraging role-models who promote a responsible lifestyle; but no relationship is worth the price if the cost is being controlled, and taking insane, dangerous risks to sneak around the limitations you're under.