Unless it's totally necessary for business, I try not to even have a married woman's phone number saved on my cell. Those I do are generally much older than me and ones I would have no temptation to cross a line with. I don't travel alone with married women either. I had a married woman try to give me a hug at work recently and when I didn't open up my arms immediately, she noticed my hesitancy and gave me a side hug without me reciprocating. I don't do what I would expect others not to do with my wife.