Even when we know it's time to end a romantic relationship, we're often reluctant to let go of our partners completely.
We've shared so much of our lives with our partner, it seems almost callous to simply cut them out of our lives-especially if we're ending the relationship on good
terms. It's natural that we want to hold onto the loving and supportive part of the romantic relationship, and simply let go of the parts that aren't serving us. This is entirely possible: we can remain friends with our former lovers. We both need to want to build a friendship, however. 

If we choose to stay friends with a former romantic partner, we will have to establish new boundaries and expectations in the relationship. The old checklists are no longer appropriate, and it may take some time to make a successful transition to the new relationship. It's best, in fact, if we do not spend any time together once we've officially ended the romantic relationship. A clean break is essential.
We need time to separate our life from our partner's. We need to reestablish our own boundaries and our own identity.
And we need to spend a little time mourning the death of the romantic relationship. It takes time for the emotional connections to adjust, and it takes time for us to gain perspective on the entire relationship.

Once we're ready to spend time with our partner again, we must recognize that any friendship that we build is a new relationship. It is not an extension or continuation of our romantic relationship. We will need to start slowly, and to build up a new level of trust. It will take some time to make sure we're using the appropriate checklists. We can't expect the same kind of support or commitment in a friendship as we did in a romantic relationship. By the same token, we may find that we could tolerate certain behavior from a lover, but that we won't accept it from a friend. 

In many ways, friendships are far more demanding than romantic relationships. We look for a higher level of shared interests and compatibility with our friends than we do with our romantic partners. We may discover that our former lovers don't make the cut as friends-and there's nothing wrong with that. We have a much easier time letting friends drift out of our lives than we do with letting go of
romantic partners.

Excerpt From "The Relationship Handbook: How to Understand and Improve Every Relationship in Your Life" by Kevin B. Burk 

 (c) Kevin B. Burk, All Rights Reserved