It is narrated from Sayyidah Asma' bint Abi Bakr (may Allah be pleased with her) that she heard a woman asking the Messenger of Allah (peace and blessings be upon him). She said: I have a co-wife, and I make a show of being satisfied by my husband with things that I do not actually receive, in order to anger her. Is there any sin upon me in that? He (peace and blessings be upon him) said: "The one who makes a show of being satisfied with what he has not been given is like one who wears two garments of falsehood."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20722