Musnad Ahmad 1167:66

Yahya ibn Sa'id narrated to us, from Hisham, who said: Fatimah narrated to me, from Asma', that a woman said: "O Messenger of Allah, I have a co-wife; is there any sin upon me if I pretend to have received from my husband what he has not given me?" The Messenger of Allah (peace and blessings of Allah be upon him) said: "The one who pretends to have received what he has not been given is like one who wears two garments of falsehood."