If that’s the case, we get why you might be tempted.But that’s not nearly a good enough reason to pursue anything beyond a hug when you run into him at the mall or the movies.
The sheer concept of seeing one of my mates with an ex is something that’d affect me for a number of reasons.
And when you don’t really trust someone, it’s hard to be friends with them.
Your friend is more than fair if she asks you how long you and her ex have entertained dating each other.
Just think about how uncomfortable it will be for the both of you for her to know that not only are you aware of some of the innermost secrets of her relationship but now, you’re going to learn about some of those things firsthand. If your friend does pretend that she’s cool with it at first (which is shocking all on its own), don’t be surprised if she’s not in the long run.
She has every reason to think that you dating her ex is a bit on the side of disloyal.