From which poem does a pear blossom crush Haitang?

A pear flower on Haitang comes from Su Shi's A Play for Zhang Xian, and the whole poem is:

Eighteen brides are eighty lang, with gray hair and red makeup.

Two nights of mandarin duck quilt, pear tree pressing begonia.

The bride is eighteen and the groom is eighty, with pale hair facing the bride's gorgeous red makeup. Mandarin ducks in pairs, like pear trees overwhelming Haitang.

The influence of a pear flower on future generations.

The poem Zhang Xi 'an Opera was written by Su Shi to congratulate Zhang Xian, an 80-year-old friend, on his wife. In ancient times, it was normal for rich people to have three wives and four concubines, so this Mr. Zhang Xian talked about an unforgettable love and married a beautiful girl of 18 years old as a concubine. So Su Shi sent such a naughty poem.

A pear flower presses a begonia because it is to write a poem to tease an elderly husband to get married, so in the process of circulation, the elegant original poem is replaced by more popular and straightforward folk jokes.