It's a big day for the robot family. The robot patriarch, X7-051, is hosting a dinner for his three robot sons, and all three of them are engaged to beautiful robot women. X7-051 is very excited to hear all about them.
As they sit down to their first course of oil soup with Li-ion batteries, he turns to his first son.
"So, X8-001, tell me about this robot fiancée of yours! I hear she's quite a catch!"
X8-001 replies, "yes father. She's made of stainless steel! I'm a very lucky robot man!"
X7-051 is overjoyed! "Stainless steel! That's wonderful! I can't wait until the robot wedding!"
He then turns to his middle robot son. "X8-002, tell us about your robot fiancée!"
X8-002 says, with a grin on his metallic face, "well father, I'd have to say I've got my brother beat. My robot fiancée is made of pure titanium!"
X7-051 chortles and slaps his robot knee. "Titanium! Why, that's space-age stuff! Very difficult to forge! I'm so proud of you, my boy!"
X7-051 cocks a robot eyebrow and turns to his third son, who has always been the black electric sheep of the family. "So, X8-003, tell us all about your robot fiancée!"
X8-003 stands up straight, puts his spoon down, and folds his napkin. "Father, I love my robot fiancée very much and I can't wait to robot marry her. I knew when we met you would never approve of her, but I can't help my feelings. My robot fiancée is made... of iron."
X7-051 jumps up in his seat, pounds the table and yells, "Iron?! Why, she's no better than a common ore!!"