We can not confuse sex with love, since they are two different things. Sex has to do with passion, that is to say with the satisfaction of the instinctive part, while love goes beyond the attraction and union of bodies.
In the case of sex by trade, they act only instinctively, that is, the animal part.
When two beings love each other our feelings act and when they unite their bodies is something very sublime and beautiful that goes beyond the passion.