Let's start with the verb cagar. Some people will tell you this means to deficate, but it really means"to shit". If you want to say "defecate", then the word is defecar. Huge difference between those two. I really hate when people don't translate things accurately, it could really get you in a lot trouble. But I digress.
You can't use cagar to say "shit!". If it's the exclamation you're looking for, then you want to say "¡Mierda!" or "¡Coño!" But we'll talk more about those in another post.
Now back to cagar.
You can use it just like you would in English:
Tengo que cagar
I have to shit
But we aren't talking about cagar today. We're here to talk about it's reflexive cousin, cagarse. And since cagarse is a reflexive verb it means "to shit yourself."
Casi me cago los pantalones
I almost shit my pants
Casi me cago de la risa
I almost shit myself from laughing so much
Me cago de miedo
It scares the shit out of me or I'm scared shitless
And while those are fun, let's get to today's expression.
Cagarse, at least in Mexico and perhaps other countries, can also be used to say something really fucking annoys you.
Me caga tu sonrisa
Your smile really fucking annoys me
¿Sabes qué me caga?
Do you know what fucking annoys me?
You get the picture, and if you want to see more examples, check out this blog page:
10 cosas que me cagan de ti... Humanidad
There are lots of great examples of how to use this phrase there. Have fun with it.
That's it for today, ¡hasta la próxima!