That’s a completely different can of fish

The speaker was trying to explain to his wife that something was another matter completely, and blurted out this conflation of “a can of worms” and “a different kettle of fish”, both meaning to describe a difficult situation or problem. “A can of worms” seems to be a phrase often jumbled, particularly with idioms involving fish, as there are other variations of this theme posted here previously. E.g. https://malaphors.com/2016/04/25/i-dont-want-to-open-up-that-hill-of-worms/ https://malaphors.com/2013/10/12/thatll-be-a-kettle-of-worms/ https://malaphors.com/2012/12/18/thats-a-real-ball-of-worms/ https://malaphors.com/2015/04/10/lets-not-open-up-that-can-of-bees/

A big thanks to Martin Pietrucha for uttering this one and when realizing it was a malaphor, sent it in.