GOLDEN RULE
Remember it's a punt for money with a working girl so NO it's not advisable to form "relationships"
In my case I've bumped into a regular occasionally and we've had a coffee. I've helped a couple with computer issues over the years and I had a regular who I met through an agency. I used to book her for 3hrs she often asked to stay the night at no extra cost we used to meet in travel lodges. But there was no relationship!