項莊舞劍，意在沛公

Etymology
From the . In 206 BC, late Qin dynasty warlord invited his rival  to a feast at Hongmen. During this feast, Xiang Yu's cousin,, tried to assassinate Liu Bang (also known as the Duke of Pei) by pretending to offer to perform a sword dance.

Idiom

 * 1) to have other disguised intentions