fucking mayo on my burger

So I go to a fast food joint and order a hamburger ,ME  being me I’m thinking they already know I like my burger with ketchup not FUCKING MUSTARD …why the fuck do ppl put mustard on a fucking burger that shit is meant for hotdogs!!!!! I bit into that shit and was like “what the fuck is that”? “wtf combination is this”hamburger-mustard-212022? Now I like a lot of shit but fucking mustard on a well cooked burger is fucked up..