It is narrated from Sayyidah Asma' bint Abi Bakr (may Allah be pleased with her) that a woman said: O Messenger of Allah! I have a husband and I have a co-wife. Is there any sin on me if, in front of her, I make a show of being filled with what my husband has not given me? The Messenger of Allah (peace and blessings be upon him) said to her: "Whoever pretends to be filled with what he has not been given is like one who wears two garments of falsehood."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 20694