Sounds to me as if this "ex" really doesn't want him back, bult, doesn't want him with anyone else either. She is confused to put it mildly and is afraid of life without him. (the unknown). Your friend needs to move on with his life. Any one, male or female, that would play this game is extremely selfish. She should let the guy go once and for all so he can find contentment in life.
I'm with you. A relationship should not be so much damn work. If it is, it's time to rethink things. :)
the ex wants to just have smex, and thats it
He is just missing the action... don't do it. He is filling a void.