As NepaliInChina indicated, Ajay and wife used to have other couple over and pick a random key from bowl of communal keys and pick a bedroom partner based on the key draw. That shows this couple was comfortable with swapping partners. Doesn't that show the wife might have stayed mum inspite of the knowledge of Ajay having sexual relationship with the adopted daughter? If true, the wife would have breached the fiduciary duty to care/ minister to the minor daughter and should be made to face the music in the court of law.

Just an observation!