Alternative form of all one's taste is in one's mouth

(idiomatic, mildly insulting) One lacks good taste in aesthetic or cultural matters.

(informal) Trouble will happen soon.

(less common) Alternative form of the proof of the pudding is in the eating

Someone is having a period of good fortune. / (in particular) Someone is the object of another person's sexual attraction.

(idiomatic, chiefly in the negative) Someone is emotionally invested in (something); someone does (something) wholeheartedly.