Grandpa: We were all young and foolish back then, Billy. We didn't think about the future. We just wanted things. This creature shows up, and it seemed like a good deal, for everyone in town.
Stan Marsh: You didn't stop to think about what it would mean for us?
Grandpa: We thought about it. But our town was so tiny back then. We just- we wanted nice things other people had.
Stan Marsh: And you didn't give two shits what it would mean for your grandchildren?
Grandpa: I didn't think I'd have grandkids! I didn't even want children! That's why I always came on Gram Gram's tits.
Stan Marsh: [Groaning in disgust] Ahhhhh!
Grandpa: But then, one night, I'm having sex with your grandma, and she sticks her finger in my ass. She had sometimes licked my ass before, but this was the first time she used her finger, and I came inside her like that. I pulled out, and your grandma was like, "Did you just come in me?" And I was like "Well, you stuck your finger in my ass." And that's basically why you're here, Billy.
Stan Marsh: This is supposed to make me feel better?
Grandpa: I'm just saying that I wasn't thinking about the future because your father was supposed to be nothing but dried up crust on Gram Gram's titties.