adultery
He had admitted having an adulterous relationship.
She confessed to killing her adulterous husband.
It was like making a date that could lead to some kind of adulterous romance.
SMART Vocabulary: related words and phrases Disloyalty, betrayal & treason
backstabber
betrayal
betrayer
break ranksidiom
chicane
collaborate
deserter
desertion
faithlessly
faithlessness
false
fifth column
fifth-columnist
stab someone in the backidiom
tergiversation
throw someone to the lionsidiom
throw someone under the busidiom
traitor
treasonable
unfaithfulness
You can also find related words, phrases, and synonyms in the topics:
Relationships: infidelity