Esio Trot by Roald Dahl

From the bestselling author of Charlie and the Chocolate Factory and The BFG! 

Mr. Hoppy is in love with his neighbor, Mrs. Silver; but she is in love with someone else—Alfie, her pet tortoise. With all her attention focused on Alfie, Mrs. Silver doesn’t even know Mr. Hoppy is alive. And Mr. Hoppy is too shy to even ask Mrs. Silver over for tea. Then one day Mr. Hoppy comes up with a brilliant idea to get Mrs. Silver's attention. If Mr. Hoppy's plan works, Mrs. Silver will certainly fall in love with him. After all, everyone knows the way to a woman’s heart is through her tortoise.