PDA Public Service Announcement

pda: when is enough too much?
What's the most flagrant offense you've seen or participated in?
Does your general attitude towards this change when it involves you?
Is this all culturally-bound, anyhow? For instance, how come when you're strolling the streets of gay Paree, lovers in the rain are just... lovers in the rain... and here in America, even the word "lover" becomes hopelessly creepy?