Alternative form of butter my butt and call me a biscuit

(idiomatic) The identified person appears to be benign, mild-mannered, or calm (but with an integral suggestion that, to the contrary, he or she really is untrustworthy, disagreeable, or mean-spirited).

Alternative form of butter wouldn't melt in someone's mouth

Alternative form of butter wouldn't melt in someone's mouth

(idiomatic) To profit from two things at the same time, especially when those things seem contradictory or incompatible.

Synonym of like a knife through butter

present participle of butter someone's biscuit

simple past tense and past participle of butter someone's biscuit

Third-person singular simple present indicative form of butter someone's biscuit

(Southern US, colloquial) An expression of astonishment upon learning something unbelievable (usually positive).