两面讨好 liǎngmiàn tǎohǎo
[trim;be on both sides of the fence; fuctuate between two parties so as to appear to favour each; run with the hare and hunt with the hounds; try to keep favour of both sides] 在两派之间摇摆或保持中间立场以讨好双方的人
两面讨好,以求万全