How attached are you to him?
You need to be honest with yourself in order to avoid drama in your current relationship. If you feel any emotion when you think about your ex, chances are, you’re still attached to him. There should be absolutely no unresolved feelings between the two of you, before you can have a good friendship.
How was the break up?
If the break up was a mutual one, then your chances of remaining friends are very high. People often take time to get over messy break ups. If you’re still seeking closure from your past relationship then you might want to wait before deciding to be friends.
How does your man feel about it?
You two broke up for a reason and it’s really best you keep it that way. However, If you insist on maintaining somewhat of a relationship it’s best you find out how your current partner feels about it. You don’t want to ruin something good over an ex.
What are your intentions?
The both of you need to be clear of why you want to remain friends. Are you doing it because your friendship was stronger before you started dating or just doing it to get back in each other’s pants?
Will you be tempted?
You need to be very sure that there won’t be any form of sneaking around because then you’ll be betraying your current partner. If you still find him attractive or drool at the thought of him, then you might just want to stay as far away from him as possible because you can be tempted to get physical with him.