東床

From a tale in the Book of Jin about the renowned calligrapher Wang Xizhi:

When Xi Jian―the Grand Tutor to the Crown Prince in the Eastern Jin dynasty―wanted to select a son-in-law from the Wang family, all the eligible young men in the Wang family were trying to impress the envoy sent by the Grand Tutor when he came. The only exception was Wang Xizhi, who was lying nonchalantly on his bed, eating something with his belly exposed.

The Grand Tutor was informed of what the envoy had observed, that all the young men of the Wang family were fine-looking, albeit reserved, excepting a young man who lay on a bed in the east with a bare abdomen. The Grand Tutor remarked: “That is the one I want as my son-in-law!” He visited the Wang family himself, realised the young man was Wang Xizhi, and gave his daughter to him in marriage.

東床

1. (figurative) son-in-law

   東床快婿／东床快婿  ―  dōngchuáng kuàixù  ―  good son-in-law

   • 因未有室，賈赦見是世交之孫，且人品家當都相稱合，遂青目擇為東床嬌婿。 [Written Vernacular Chinese, trad.]
     因未有室，贾赦见是世交之孙，且人品家当都相称合，遂青目择为东床娇婿。 [Written Vernacular Chinese, simp.]

     From: Cao Xueqin, Dream of the Red Chamber, mid-18^th century CE

     Yīn wèi yǒushì, Gǔ Shè jiàn shì shìjiāo zhī sūn, qiě rénpǐn jiādàng dōu xiāng chènhé, suì qīngmù zé wéi dōngchuáng jiāoxù. [Pinyin]

     Seeing that [Sun Shaozu] is unmarried and is the grandson of the Sun family (a family of longstanding friendship with the Jia family), and there is a good match in characters and family backgrounds, Jia She favours him to be the son-in-law of the family.

2. (figurative, literary) guest bed