Walk directly past the sour cream. Do not buy sour cream.
Redditor Blinkinator's girlfriend has some trust issues. She isn't afraid he'll cheat on her; she's afraid he'll freak out and buy the wrong frozen mixed vegetables. She drew him a map of where to find the buttermilk. She has so little confidence in his ability to do a simple task that she even gives him instructions for what to do if he can't find an item: ask someone who works there.
And oh, then she has to go and humiliate him by telling him he can pick whatever tortilla chips he wants (he picked Tostitos, for the record). That smiley face is devastating. You are a child, Blinkinator, and your girlfriend knows it.