Amr bin Shu'ayb narrates from his father, and he from his grandfather (Sayyiduna Abdullah bin Amr, may Allah be pleased with them both): "There is no li'an between four (kinds of women) and their husbands: (1) a Jewish woman married to a Muslim, (2) a Christian woman married to a Muslim, (3) a free woman married to a slave, and (4) a slave woman married to a free man."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب اللعان / 15302