Yahya related to me from Malik from Ibn Shihab that Zayd ibn Thabit said, "When a man takes his wife to his house and co-habits with her then the bride-price is obliged."
Yahya related to me from Malik that he had heard that Said ibn al-Musayyab said, "When a man comes to his wife in her room, he is believed. When she comes to him in his room, she is believed."
Malik commented, "I think that this refers to sexual intercourse. When he comes in to her in her room and she says, 'He has had intercourse with me' and he says, 'I have not touched her', he is believed. When she comes in to him in his room and he says, 'I have not had intercourse with her' and she says, 'He had intercourse with me', she is believed."
28.5 Wedding Nights of Virgins and Women Previously Married