Using idioms

When I studied at Technology College, a classmate had a sweet tooth. She always bought some candies, cakes and fruits. Another classmate learned all the Math’s expressions by heart. They fell head over heels in love. After finished the Technology College, they decided tie and knot and see eye to eye on almost everything. They bought a large house which costs an arm and a leg. Now they sold the house, shake a leg, they became rich men.
There has a big mouth person who heard this story; he is nosey about the couple. I couldn’t tell him anymore, so he had a long face. Finally I told him that I just pulled his leg.