It does sound like you've already made up your mind (judging by your comments) and you're just looking for some responses that will make your actions justifiable. In the end, you will ignore all others who are against sleeping with your friend's ex.
Personally, I wouldn't do it, especially if he has still feelings for her. The question is would you mind if you were in your friend's situation and a friend of yours came along and slept with your ex? Act depending on how you answer this question.
Personally, I wouldn't do it, especially if he has still feelings for her. The question is would you mind if you were in your friend's situation and a friend of yours came along and slept with your ex? Act depending on how you answer this question.