Couples therapist Esther Perel , author of “Mating in Captivity” and “The State of Affairs: Rethinking Infidelity” and the host of the Audible original series “Where Should We Begin?,” reveals why people can be friends with an ex and how you can maintain that friendship and your current relationship.
Esther Perel: In the past, when a relationship ended, that was it. Most of the time you had no way of finding the person anymore. You had moved. They had moved. Who knew?

Today we have the capacity to actually go and find out whatever happened to that person. And what’s their life like. And what would my life maybe have been like if I had stayed with that person. I get to actually have a glimpse into the stories that I didn’t choose to live.
see how here>>http://infopromoter.com/2017/10/30/heres-how-to-stay-friends-with-your-ex/

Staying friends with an ex brings back old feelings, and you don't want that, just cut them off completely.