From China Digital Space
wěn dìng 稳腚
Starting with former president Hu Jintao, the Communist Party has gone to great lengths to "maintain stability" domestically. Using this rationale, protests are squelched, political dissidents controlled, and media censored.
Netizens joke that the only things "maintaining stability" are the seats of the leadership on the throne of power. "If you want social stability," a netizen once wrote, "officials can't have 'stable bottoms'" (要想社会稳定，官员不能“稳腚”).
Netizens play up the anatomical imagery, such as in this Weibo post:
Xiangxianzhong001 (@项先中001): harmony, stable bottoms (May 1, 2016)
See also stability maintenance.