Ok, here's the deal. I say when Cartman got abducted by aliens and they gave him an anal probe, they also completely screwed with his DNA to the point that you can't tell what his parentage is. Any tests will come out screwy.
There's another possibility, of course. Cartman could have access to a time machine and could become his own father. He was in the room when Memphisto said "It's someone in this room." Crazier things have happened.
Whatever you do, please don't take me too seriously, mmmmkay?
Brian T. Perkins [email]
"You know, I've learned something today."