《魏书·列传·卷八十八》
男女初婚那天晚上，男子去到女方家中捉弄一下女子的乳房就住手，用这种方式作为定婚，两人便成为夫妇。
初婚之夕，男就女家执女乳而罢，便以为定，仍为夫妇。
On the night of the first marriage between men and women, the man goes to the woman's house and tricks the woman's breasts, and then stops. This is used as a way to get engaged, and the two become husband and wife.