I Know Him So Well

From the musical Chess.

Written by Tim Rice, Bjorn Ulvaeus & Benny Andersson.

It was originally sung by Elaine Paige (as Florence) and Barbara Dickson (as Svetlana). In this duet, two women – Svetlana, the Russian chess champion's estranged wife, and Florence, his mistress – express their bittersweet feelings for him and at seeing their relationships fall apart.

Lister here:- https://www.youtube.com/watch?v=oou1Lhw2ijI