1‘her husband never knew of her infidelity’
unfaithfulness, adultery, unchastity, cuckoldry, extramarital relations, extramarital sex
faithlessness, disloyalty, falseness, breach of trust, treachery, double-dealing, duplicity, deceit, perfidy, perfidiousness
affair, liaison, intrigue, amour
informal fooling around, playing around, playing the field, cheating, two-timing, hanky-panky, a bit on the side
We take a look at several popular, though confusing, punctuation marks.