Personally, I'm all into mutuality and making sure everyone's getting everything they want. But some people will, on occasion, find that to become tedious or implausible... maybe they don't have the skill to please their partner, or maybe they usually do but occasionally they want to be really indulgent and not have to bother. When you pay someone, it becomes all about the person who paid.
all of which is precisely what would take it out of spiritual context imo. not speculating on the morality of course- i don't have an opinion either way in that sense.
and really, that is not to say that the experience still couldn't be spiritual, but i think the odds at play here make the instance of a "spiritual experience" with this method, an exception, at best.