“That burrito I ate didn't agree with me.”

You're out with a friend and your stomach started to feel upset. Your friend asks you about it, and you explain what's happening:

That burrito I ate didn't agree with me.

burrito

A burrito is a food item that's popular in American versions of Mexican food. It's some kind of meat, beans, and sometimes rice, grilled onions and peppers, or other fillings, all wrapped in a piece of thin flat bread called a tortilla.

(some food) didn't agree with (someone)

When food gives you an upset stomach, you can say that the food "didn't agree with" you. It's a way of saying that the food made you feel sick.

You can say that something "didn't agree with" you even if it just makes you feel a little bit sick. It doesn't have to be a very strong negative reaction.