(humorous, idiomatic) what does that have to do with the price of tea in China?

(idiomatic, vulgar) Expression of approval. / (idiomatic, vulgar) not a chance; no fucking way / (idiomatic, vulgar) definitely; no fucking doubt

(idiomatic) no pain, no gain

(idiomatic) if you're born to be hanged, then you'll never be drowned

(idiomatic) it cuts both ways, something is a double-edged sword

(idiomatic) no smoke without fire

(humorous, idiomatic) when the cat's away the mice will play

(idiomatic) don't mention it (you're welcome) / (literally) Used when the speaker thinks there is nothing to say; there's nothing to tell!

(idiomatic) the grass is always greener on the other side (literally "everywhere is good where we are not")

(idiomatic) when the cat's away the mice will play