三馬同槽 [－马－－]

Jyutping saam1 maa5 tung4 cou4
Pinyin sān mǎ tóng cáo

Definitions (CC-CEDICT)
  1. three horses at the same trough (idiom, alluding to Sima Yi 司馬懿|司马懿[Si1 ma3 Yi4] and his two sons); conspirators under the same roof