磕头碰脑 kētóu-pèngnǎo
(1) [bump against things on every side;push and bump against one another]∶指人多、东西多互相挤碰
一大群人磕头碰脑地挤着看热闹
(2) [not get along]∶比喻人与人之间闹矛盾
街坊邻里有个磕头碰脑的事,他都出面调停