The shoe is on the other foot:it means the situation between us has changed,somebody has replace someone to stand on the top place.
（风水轮流转的意思）
For example,for the last ten years the Tigers have been the worst team in the league,we've finished down at the bottom.But now the shoe is on the other foot,we have all these good young players and we're beating everybody else in the whole league.（在过去的十年里,我们“老虎队”一直是参加联赛的所有球队中最差的一个,比赛总是最后一名.现在不同啦,我们的队员都很年轻,球技也好,“老虎队”目前所向披靡.
）