Humiliation Conga: One long one for George. His archenemy Archie inviting himself to Lionel's engagement party is just the beginning. When Archie arrives at the party he's basically The Gadfly, humiliating George's beloved (and terrifying) mother by calling her "Mammy" and is then there to witness the ultimate humiliation when George learns his son's fiancee is the product of a mixed marriage. To top it all off, his future daughter-in-law's white father then manages to steal a dance with his own wife. Apparently resigned to his misery, George has a rare bonding moment with Archie over drinks at the end.
Maligned Mixed Marriage: Archie and George's first reactions when they realize Tom Willis is white and his wife, Helen, is black. Which is why Lionel puts off introducing his future in-laws to his father as long as possible — he accurately predicts his reaction.
Mammy: When Olivia "Mother" Jefferson is trying to tell George to hold off on the drinking and he tells her to back off, Archie — who is right there — tells him he ought not to backtalk his mother ... and lets slip the word that deeply upsets Mother Jefferson. Archie tries to justify, but gets nowhere of course, the use of the word by suggesting that all black people refer to their mothers as "mammy" ... including Al Jolson (who was white and performed in blackface).
N-Word Privileges: At least once, George — of all people — utters the dreaded n-word. Archie makes a sly remark that he's not used the word "nigger" in three years ... which is a Shout-Out to the fact that none of the scripts have ever had Archie use that word (he'd use euphenisms such as "coon" instead). note (A later episode, "Two's a Crowd," will reveal that Archie used the word once as a child to insult an African-American classmate and got a severe beatdown for his trouble, hence why he rarely if ever used the word again.)
