“As the years have moved on, our explosions have become far less frequent as we have learned to live with each other, accepting each other’s edges and corners.”-Two-Part Invention by Madeleine L’Engle
I love that phrase “edges and corners”. We all have them. At times I have been like a dodecagon (yes, I looked it up), all full of edges and corners plus prickles like a porcupine. But, as time wore on, I was more like the glass I ordered a few weeks ago. I bought a piece of glass to put on top of my great-grandmother’s sewing machine so I could use it for a table. They beveled the glass so the edges would be smooth and polished. I think Chuck and I both became more rounded and mellow over the years. We argued less and gave more than took from each other.
It is rare and wonderful when family members are best friends. – A Grace Disguised by Jerry Sittser
Chuck and I were best friends. I count my brothers as pretty good friends, too.
Not In This Soup Alone 
I love the metaphor! After 20 plus years of marriage I think we still have some corners and edges, but you are right that other parts have worn off and become smooth like glass.
I imagine you and your wife have been polishing each other’s edges and it will only get smoother!