On April 28 1945, at the Piazzale Loreto in Milan, Benito Mussolini and his mistress Clara Petacci were shot and hanged in a spectacle that was photographed repeatedly.
Someone who has had a mistress is Benito Mussolini.
( z1 someone :ARG0-of ( z2 have-rel-role :ARG1 ( z3 person :name ( z4 name :op "Benito" :op "Mussolini" ) ) :ARG2 ( z5 mistress ) ) )