<human>: Let me begin with apologizing if my english is incorrect. I am not a native speaker. 

My Fuck up happend a few months ago. It was around midnight when we(me and two friends) decided to go get some burgers at Mac  Donalds. As we're driving through the mc drive i spot an old lady working there. I jokingly tell my friends that she must really like working there because at that age you should not be working at a MC. Until now nothing weird is said and i continue by telling my friends that i think its even worse for an older woman to work in an school cafeteria. This is where it becomes quiet in the front of the car. As the dumdfuck as i am i should have noticed this, but unfortunately i continued to belittle woman in school cafeterias. I tell them about this woman in my school a what a bitch she is. Still not noticing the quietness in the front. Soon i get too the point where i call all school cafeteria woman a bitch. 
This is where my friend slowly turns his head around. He looks at me and tells me his mom works in a school cafeteria. 

My face turns red as i realize i've done fucked up.

Can you give me the gist of the text in a nutshell?
<bot>: told friend older woman that work in school cafeteria are all bitches. Turns out his mom works in a school cafeteria.