Could I date an ex escort/ get married to her? 100% yes. All depends on the circumstances.
Could I date/get married to an escort who tells me we are a couple but my escort work continues as that is my job just like you have your job but for sure you will know I'll always be in your bed come night time (unless I get a lucrative overnight offer) 
. 100% no!
My last gf (of a couple of years) told me she'd been a WG on-off for a short period some years previously. I also told her I used to punt (I've never punted while being in a relationship). It was no problem for either of us. She'd needed the money (kids, but no man around), but having said that she was (and I'm sure still is) very highly sexed and would want it every time we met/went on holiday.
We split up for unrelated reasons.
But I couldn't handle being in a relationship with a currently working WG. That would do my head in.
