Okay, you got me, luke. Prostitution doesn't apply in the "two people desiring each other" instance. I suppose I should broaden it, and so I will make a third instance. I listed the other two already, above. The thrid case is if you believe sexual intercourse is on par with any other thing, and has no special traits, except the procreation side effect. It can be given, it can be sold, it can be shared. And just as any other item a person possesses that another may want, it can be stolen, (rape). in this sense, it exists only for a form of happiness, and in the case of prostitution, two forms of happiness, one being the orgasm and the other being the money. In my opinion, this is sad. I hope to never be reduced to that.