In William Shakespeare's tragedy Julius Caesar, one of the primary leaders of the conspiracy against Caesar is Brutus, who is the husband of Portia, who was the daughter of a famous Roman nobleman known as Cato the Younger.
In Act 2, Scene 1, the conspirators have been meeting in Brutus' orchard in the middle of the night and their plans to kill Caesar will be set into motion a few hours later.
After the conspirators leave the orchard, Brutus is started by Portia, who wonders what her husband is doing and what is bothering him. He tells her that he is "not well in health".
Portia, however, suspects that Brutus is healthy physically, but that he is mentally troubled. Portia begs Brutus to tell her what is wrong with him. Brutus appears to be on the verge of telling Portia "The secrets of [his] heart" and "All my engagements", but a knock at the door interrupts him. Before he can reveal anything more, he sends Portia back into the house.
As for whether Brutus does tell Portia about his part in the conspiracy to kill Caesar, the audience does not hear this conversation. We do see Portia again in Act 2, Scene 4, and her words and deeds in this scene appear to indicate that she is aware of what Brutus is about to do.