Having a second sim is smart but I hate the process of swapping round these nano sims, seeing how smartphones are now so cheap, I have two. Main expensive one for my friends,families and work and a second £50 one for escorting. That way you can have all the benefits of the smartphone contacting escorts through watsapp, web browser, and GPS, etc. A sim card costs a £1.00. Nowadays if you we're really paranoid you could have multiple sim cards for escorts.
I used to have a nice deal on my EE sim before I left the country. £10 for 500mb of data, unlimited texts and 90mins of calling on PAYG. More than enough for any potential eventualities. And better than a dumbphone. Which in this day and age is actually more suspicious if someone finds it and asks why you have one.
Also having a smartphone means you have something to connect as a internet device at home that only you use. Especially wise for those of you who share computers and iPads with others and still do escort research on them. Which I personally think is crazy.