Yazid bin Yazid bin Jabir (may Allah have mercy on him) said: I asked Mujahid (may Allah have mercy on him) about a man in ihram who has intercourse with his wife. He said: This happened in the time of Sayyiduna Umar (may Allah be pleased with him), and he said: The two of them (husband and wife) shall complete their Hajj, and Allah knows best about their Hajj. Then when they return, each of them is lawful for the other. But when the following year comes, the two of them (husband and wife) shall perform Hajj again, offer a sacrifice, and separate at the same place where they committed the sin.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9781