Swallow Wei Zi competes with May.

Swallows fly, chasing in May, Master Erkang loves crape myrtle, and the emperor chases Princess Xiang on horseback. Galeries Lafayette turned black with anger. Sunny, don't worry, I will send Xiao Jian to marry you.

Well, there are many other versions, such as:

Swallows fly, may chase, Erkang falls in love, the emperor fights for concubines, and Sister Rong is a turtle (I like this sentence: p).