mathematical equation

I have posted earlier about being friends with your ex and if it is even possible... So the brief history behind this story is that my ex and I (now my real ex, I do not count these guys that I dated for like one month or so because I mean they are just not important) broke up last year - end of August. Correction = he broke up with me. 

He broke up with me and then it showed that he immediately started dating this 21 year old 'model'. No judgement - but the girl is beyond crazy. Anyways they dated for some time and they eventually he ditched her too.

Anyways, I was devastated when he broke up with me but then again, being left hurts... Time passed and I got over him in a timely fashion and then slowly we started talking again. Now when this girl found out about that she lashed out on me, classy! So she started telling me that they had an affair when I was still together with him and that I am a fat pig, etc. I mean I received these messages at 6 a.m. after a night out so you can probably imagine my reaction. And the thing is that she did not stop there - she continued months after verbally attacking me with God knows the petty insults that she threw at me. There might be some truth in what she was saying even though my ex denies it, but I don't believe their one of them because I don't trust them. Anyways, back to what I wanted to get out of this train of thought: 

I believe that I have to back my statement that you can be friends with your ex. Since we broke up we have hung out a couple of times, more than exes should hangout but it felt fine. We sleep at each others places (which I have to say is a big no no), we go for dinners and drinks AND we started hanging out with groups of friends again. I mean doesn't this send the wrong message? I mean I am fine with it because I have no expectations from this relationship or relation or THING that is happening between us since he already broke my heart once. But due to the fact that we were never friends before dating, the friendship that we are now trying to build is a way of breaking down the relationship that we once had. 

It's like a mathematical equation.

a3−3a2b+3ab2−b3 = (a−b)3

Then = Now

This is an easy example but the main idea being that we were thing: a3−3a2b+3ab2−b3, and now we are trying to be: (a−b)3. But in the end: (a−b)3 is a3−3a2b+3ab2−b3. The complex parts will never go away. And this is something that either we learn to live with or there will come to a point when all that complexity will end the friendship or THING that we are now trying to build. 

This quote is how I feel towards a lot of my ex's, but not him... yet. I really do hope that we can stay friends but it is really hard trying to decide how the relationship is suppose to be when you once loved each other. Maybe being friends with your ex is a way of holding on to the past until you are ready of letting go...?