Charlie tries to avoid meeting Chelsea's parents by making up a colonoscopy appointment.
Alan, Jake and Berta welcome Charlie and Chelsea home.
Despite his best attempts to avoid meeting Chelsea's parents, he finds them in his living room.
Charlie gets a colonoscopy in order to avoid spending time with Chelsea's parents. Makes sense.

Two and a Half Men Season 7 Episode 13 Quotes

Alan: Okay let me see if I got this straight: in order to not spend time with your fiance's parents, you're going to let a doctor snake a camera up your kiester?
Charlie: I'd be willing to let them shoot an IMAX feature.

Charlie: I'm out of baby wipes.
Chelsea: I bought you two boxes of baby wipes.
Charlie: What can I tell you, babies don't crap like this. At least not healthy babies.