Shuōhǎo yìqǐ chīfàn, jiéguǒ tā línshí fàng le wǒ gēzi.
We'd agreed to have dinner together, but he bailed on me at the last minute.
Tips
grammar
Literally 'to release pigeons'. It splits around the person let down: 放我鸽子 'to stand me up', 放了他鸽子 'stood him up'. The passive 被放鸽子 is the usual way to complain about it. Online, 鸽 alone works as a verb: 鸽了 'flaked'.
