Thise olde dotardes holours, yet wol they kisse, though they may nat do, and smatre hem. Certes, they been lyk to houndes, for an hound whan he comth by the roser, or by other bushes, though he may nat pisse, yet wole he heve up his leg and make a contenaunce to pisse.
Modern English:
These old aged lechers, yet will they kiss, though they can not do, and defile themselves. Certainly, they are similar to hounds; for a hound, when he comes by the rosebush or by other bushes, though he can not piss, yet will he heave up his leg and make a pretence to piss.
– Geoffrey Chaucer
The Canterbury Tales, The Parson’s Tale. The Parson on the subject of lechery, specifically old lechers. He says they defile themselves because they will kiss though they cannot do, like a dog lifting its leg at a bush pretending to piss.