APAD: Age before beauty.
This means that old people should be served first, and the beautiful and young
should be served or assisted later. However, it is mostly used by old people in
a funny way to flatter the young people. It's often rude for a young man to say
this to an older woman.
It is recorded that Mrs. Parker and a snooty debutante were both going in to
supper at a party: the debutante made elaborate way, saying sweetly "Age before
beauty, Mrs. Parker." "And pearls before swine," said Mrs. Parker, sweeping in.
[Disclaimer: I copied all the above elsewhere.]
Old age seems a stigma and handicap people don't want to face. It's humor for the
old to say "Age before beauty" but insolence for the young.