I feel your pain about having to say "we are separated" when people accidentally loop you into a conversation together,
One thing that has helped me to hurt less while answering is to have a standard response.
Mine is -
We are separated. We have been best friends for 14 years, and I hope to be friends for the next 14.
I know it hurts, it will hurt for a while. But every day it hurts just a little less. There is hope.
Me: 35 Her: 33 D : 16 S : 9 Together: 14 years Married: 12 She left 4/14/2014 Separated: 5/25/2014 OM Confirmed 7/2014 She filed 8/7/2014 I Filed 10/21/2014 Divorce final 2/12/2015