Horses were a symbol of sexuality in medieval culture. The horse in "The Reeve's Tale" is especially a symbol of sexuality because he's a stallion, released into a field with a bunch of mares. He eagerly runs off to copulate with a joyous cry of "wehee!" (212). The difficulty the clerks have in catching him probably represents the difficulty of containing the sexuality of young and lusty people (like these two clerks). It's also a foreshadowing of the rampant sexuality soon to come in the miller's house that night, when John and Aleyn have sex with Symkyn's wife and daughter. The horse's release might be the story's way of signaling that a period of sexual freedom has begun. It's also a way of signaling that what we're reading here is a bawdy story – one that's all about sex, sex, and more sex.