Yeah... I know! But your examples represent a person loathing something yet continuing to perform the act they loath of their own choice. To make it equate to being raped, the person would have to be forced to eat/smoke from a second party. Therefore the examples are not equal to being forced to have sex and the body reacting positively to the physical stimulus of intercourse (a natural response).You can enjoy something and simultaneously not want it. It's called cognitive dissonance and causes the emotion we call guilt. Many smokers know smoking is bad for them and wish they didn't smoke, but simultaneously crave and enjoy smoking cigarettes. Same goes for people dieting who break their diets and have chocolate/fast food/etc.
It's not impossible for someone to enjoy something but consciously not want it.