It can be hard at times, but for some girls it is no problem to be 老友记 with an ex.
The key is in how the relationship has ended. It's important that there is no anger and no one has cheated. If this is true for 你 then it is 更多 than possible that with a little time 你 two can go back to being friends.
老友记 and just friends. 你 must be clear about what 你 want. Sometimes when we pretend to want to be 老友记 with our ex, we are really looking to get back together. Sometimes this is what 你 want and it works, but if it goes wrong then things will be even worse.
Give him space. If after some time apart 你 still want to continue to spend time together without wanting to be a couple, then 你 are ready to be 老友记 again!
-source: justjared T.V show<>