butter up
To be nice to someone, by flattery or other means, before delivering bad news or asking for a favor. I tried to butter up my father by mowing the lawn before I asked to borrow the car. At least butter me up before you ask for money.
butter someone up
and butter up to someoneto flatter someone; to treat someone especially nicely in hopes of receiving special favors. (See also something on thick">spread something on thick; soft soap.) A student tried to butter the teacher up. She buttered up the teacher again.
butter up
Excessively praise or flatter someone, usually to gain a favor. For example, If you butter up Dad, he'll let you borrow the car. This term transfers the oily, unctuous quality of butter to lavish praise. [c. 1700]
butter up
v. To praise or flatter someone in order to make him or her more receptive or willing: My coworker, hoping for a raise, is always buttering up the boss. If we butter up the bartender, maybe he'll buy us a drink.