My understanding is that the definition of prostitution is a customer paying a provider for sex. Porn however is a customer paying a performer to have sex with another performer or a performer engaging in sex during the course of a performance which is protected by the first amendment.
Under the law, this offers customers of EMPs a legal method of taking care of business. First assume that we go to EMPs because they are safer and generally easier to deal with. Now instead of the traditional set up, the EMP works like this:
You pay the house an "equipment usage fee" of various rates depending on how much equipment you are going to use.
The house then legally labels you a performer and asks you to improv a sex scene with another performer.
Nothing is recorded as it's a private performance.
As you leave the house pays you for this performance some small amount. For instance if you paid a $80 fee for a half hour of usage your pay would be $20.
By doing this, you'd be protected by the 1st amendment. In court this defense would hold more water than "two consenting adults".
While this seems like a big hassle, this also seems like the best way to make EMP's or the like legit.