The story
In 62 BC Publius Clodius Pulcher sneaked into the festival of the Bona Dea, hosted by Julius Caesar’s wife, Pompeia, with the intention of seducing her, leading to Publius’s arrest and trial. After the trial, Caesar divorced Pompeia, and when questioned said “my wife ought not even to be under suspicion,” as Pompeia was under suspicion of illicit behavior.
Etymology from Wiktionary, CC BY-SA 4.0.