We watched a show a few years ago where various families went on different types of holidays and the dad of the super posh boho family was called Kestrel. There was a bit where he was in a v expensive restaurant in Dubai and stuck his fork in his champagne glass and swooshed it round and his wife went, "Kez.....", and he replied, "what? You know I hate the bubbles".
Consequently "a bit Kestrel" is now longhand for "wanky AF" in this house.