Stage one: refusal to accept. "No! I'm pretty sure that was somebody else, or something."
Stage two: disgust. "Oo, yuck, I'm covered in sick!"
Stage three: embarrassment. "And so is he..."
Stage four: panic. "What am I going to do!?"
Stage five: anger. "I mean, how was this my flipping fault, anyway? He swerved the taxi!"
Stage six: depression. "This is all my fault, and everybody's gonna hate me, and I'm gonna walk around for the rest of my life being teased, and they're gonna make me pay, and I'm probably gonna die or something... mumble mumble groan...."
Stage seven: acceptance. "Oh well, better clean the sick up, first."