pear shaped

A British expression used to indicate that something has gone horribly wrong with a person's plans, most commonly in the phrase "It's all gone pear shaped." The origin is unclear, but one theory says that it is RAF slang relating to the difficulty of performing aerobatic loops, which were described as "pear shaped" if executed imperfectly.

A term meaning "to go to hell in handbasket" or "when the shit hits the fan." Reportedly of British or Cockney origin, from the Royal Air Force's description of circular flight paths gone awry, or "pear-shaped."

Also may relate to a popular French Revolution caricature of "citizen King" Louis-Philippe, drawn by Honore Daumier and Charles Philipon in 1832 as a jowly pear. The French term "poire," or pear, was slang for "fool" or "idiot" - and soon thereafter, all caricatures of the King were banned, pear-shaped or not.

Quite often people's shapes, are compared to fruits, like pear, melon, or banana shaped.
The only shape that has no fruit connected to it is the hourglass shape.

Body parts like breasts can be compared to shapes too:
Melons (full and round), pear shaped (half full, most people have this), pointy (where the nipple sticks out), hangtits (hanging banana's), or flats (no tits)

when the shit aint goin right

If you are to have a large evening that consists of consuming ridiculous amounts of either alcohol or illegal substances you are bound to end up pear shaped.When your mind and internal organs are not functioning as they should do,due to mind altering substance use, you are pear shaped.

A woman with large hips and big butt and a small waist with little or no breast.
Still a very attractive figure. Men usually prefer a big bottom then boobs.

sadly wrong, awry (usually in past tense)