I don't like the analogy. Completely different circumstances than ordering pizza. But that's not the point. The point IS if you're married and seeking sex outside of it, from a provider who happens to be convenient to you in some measure, then you're wrong. By you saying she can NEVER initiate the engagment, I think it's bullshit. If it's THAT much of an inconvenience for her to text you, this should be blatantly clear from the beginning. You contacting HER could be inconvenient to HER at times. And people may not know what's OK and not OK until you tell them.
And saying it's wrong for a provider to initiate contact with any hobbyist is BS, too. I think most single guys have made it clear that it's perfectly fine to do so.
I'll say again, if it bothers you THAT much then you need to reconsider on whether or not you should continue hobbying.