This topic is one that could bog you down in pro/con lists for all of eternity if you let it: you can ALWAYS find a great reason for rekindle the fire if you are looking for it (friendship style): for one, who knows you better than your ex? They were probably there for you during some of the hardest times of your life, and frankly, there is something to be said for the comfort of knowing that someone really gets you and what you’re going through.
But then, on the other hand, there’s the question of whether this proposed friendship has motives as pure as its your intentions may seem. On a deeper subconscious level, it’s possible that part of you is hoping to win them back.
Another thing to consider is the fact that although, say you really are only interested in a friendship, depending on the context, this may or may not be so healthy for the other person. You need to consider their feelings and not just yours.
Also “friend” is a vague term. It can mean any number of things. It is important that you take the time to specifically define this friendship and what is or is not appropriate given both of your current life situations, which includes multiple factors. As a result, some definitions are more clear than others.
Say, for example, you have a new partner and he or she goes on coffee dates with an ex every 6-12 months. Even if jealousy is provoked, that isn’t SO bad, right? No big deal (probably). However, what if your new partner’s ex is regularly showing up at your partner’s house with red wine for movie nights? That’s another story, one which has questionable intentions in most cases.
In conclusion, the question of whether or not you should be friends with your ex is a highly contextual question, one that is not a one-size-fits-all type of garment and requires a lot of thoughtful consideration.