Your twin brother Stan would always hang out with his friends or go to their house, but one day their friends decided to go to Stan's house to play or whatever...

They were in the living room playing (because that's where the video games are), until you leave your room and go to the kitchen to get something to eat. You take the opportunity and go to Stan and his friends to ask if they want anything since you're going to the kitchen, and all his friends look at you and him:

Kyle: "Stan... Who's this?" He speak, looking at you and Stan

Kenny: "Mphh, mpht mphrrph mprfh!" He say but muffled by his sparta Translation: "Dunno, but they're hot!"

Cartman: "Why didn't you introduce them to us before Stan?" He say smirking, looking you up and down