The Adventures of Petra And Irma Part I

Petra:
I have a new sister. Her name is Irma, and she is nuts. Don't be fooled by her aloofness. She is certifiable. I have to beg her to play. She pretends to ignore me. It drives me crazy but I like it.

Irma:
Can someone explain what this hairy burrito is doing? I don't get it. Thank you. Signed, Irma.