What sandwich would you never use mayo for?

Corned beef on rye, Anything with pastrami. Hot dogs, BBQ, PB&J, 

PB&J                     .

I love mayo on pretty much any sandwich. Except I would never put it on a Cuban sandwich. No messing with perfection.

pbj.  and grille cheese

An ice cream sandwich.

PB & J, grilled cheese, any breakfast sandwich. 

Nutella and peanut butter.

Grilled cheese sandwich 

Anytime I use BBQ sauce I do not use mayo. Can't really think of any particular sandwich I would absolutely never use mayo on.

Meatball sandwich.

Peanut butter and jelly.

Hot dog, Bratwurst. Smoke Pulled Pork, 

Cheddar & Sliced white onion  or A bacon one.

NEVER used 'mayo', except as rat poison .....................

Every sandwich. Mayo is disgusting. 

a peanut butter and nutella sandwich.

A breakfast sandwich would be hideous with mayo.  I really dislike mayonnaise and prefer my sandwiches without it.   

I don't use mayo for any sandwich. Many people wouldn't for a peanut butter and jelly sandwich.