When a hobo takes a monstrous dump in the planter at the bar you're drinking at.
We were enjoying our fish and chips when a hobo dropped a dirty pigeon and ruined the whole day.
Hanging one's arse over a balcony and defecating on another's head.
Charlie dropped a Dirty Pigeon all over Lloyd, and his dinner and his girlfriend. It was the greatest Dirty Pigeon you ever saw.
Dirty slag who has slept with every man in the office including peoples boyfriends and has an ugly face like a pigeon.
Oh look the dirty pigeon is bent over the boardroom table again...who is it this time? oh its my husband again