Musannaf Ibn Abi Shayba 37:169

'Abdah ibn Sulayman narrated to us, from 'Uthman ibn Hakim, from Abu Umamah ibn Sahl ibn Hunayf, who said: I heard 'Abdullah ibn 'Amr ibn al-'As saying: The Hour will not be established until people copulate in the roads like the copulation of donkeys.