Separated nearly 5 years, 4 under 18 dc together.
Both of us have moved on relationship wise but we are each others go to person.
Having 4 dc is hard and 1 DC has SEN so loads of stress, meetings, info passing, mini breakdowns happen so contact between us is daily.
Our split was a friendly realisation that we just were not a couple anymore after 14 years.
We co parent very well and support each other as frankly nobody else gets it.
Talking to a colleague today who is divorced with DC she said "you and your ex are odd. You share everything but a bed".
It has made me question if our set up is wrong.
My DP and exes DP appear to be ok with how things are but I now wonder are they really?
My DP struggled in the beginning. He hated my ex "being so present" in our life however my DC come first and I need their dad in my life to give them good parents so he was given the option of stay or leave.
Exes DP was cold towards me at first but after a few years I think she knows I am not a threat so now when we are together is polite and not awkward.
I see mine and exes contact getting less with each passing year as dc become more independent. I do not want it to go completely but i see us naturally drifting apart. I am just not rushing it.
Sorry for the long post it was not intended. 
So AIBU to still love my ex because he is a good dad and friend and i am happy with how it is or should things be more "seperate" and ex like?