That and she has to feel comfortable and safe with the encounter. My wife travels for work periodically, so she had a unique opportunity. A married co-worker hinted interest in a clandestine fuck experience.I think the key is the right guy. If she is in theory open to it, just takes someone she has enough attraction to.
She was very hesitant on 'playing' with a co-worker, but this guy is married and is not local (he lives 7hrs away). She also made sure to let him know that she wasn't secretly 'playing', that I knew and approved her to experience her fantasy.