Why not put her into his confidence before they started?
"That," said I, "is a delicate question which only you yourself can decide.

By following my plan you get away at once, which is the most important thing.

Once comfortably away, you can choose the opportune moment." "There's something in that," he replied; and, after thanking me for my advice, he left me.
I do not defend my plan.

I admit it was Machiavellian.

My one desire was to remove these two dear people from Wellingsford for a season.
Just think of the horrible impossibility of their maintaining social relations with the Boyces ....
By publicly honouring Boyce, Sir Anthony had tied his own hands.