I think sexting is a big no before a date, unless of course you are happy for it to a) just be sexting, or, a free wank service for the both of you b) just a one night stand.
I used to think it was fine and was just creating a bit of chemisty. I was wrong, benefits of experience i guess. My guage now is ' would they say this to my face the first time we met' if the answer to that is no, then i might say something if i liked them, or, just cut them off. I got quite fed up as being seen as a free porn service. Just because im single and on a dating website does not mean i am selling myself. it is not ebay.
i got caught out many times with the thinking it was flirty banter, so the ' would they say this to my face' thing is quite good.
As a personal thing, im not interested in someone straight out of a marriage. Yes, i understand there could be reasons why they are ready to date, but they are still likely to be sorting out the divorce and the stresses and upset over that and i just dont want to be part of that. I would also someone had re discovered themselves first, rather than was on the rebound.