He's terrified of breaking the law (or even the Mormon law). He tried the illegal way a couple of times but there was no convenient big scary Hof-man for him to tattle on when the hooker refused to fuck him unless he paid up some more.
He won't try illegal again because there's no way he is guaranteed to get the sucky-sucky-oh-you-big-stud that he wants, and I'm pretty sure that 90% of street hookers could kick his manlet ass. We debate on whether or not he'd rape a woman but he'd have to have some kind of serious advantage, like a weapon. You don't pull a gun on your girlfriend in the 80s romance movies, so I can't see him packing heat to a "date". Therefore, he's completely at the mercy of the hooker, and he knows it, and he hates it.