A longman is typically an individual who chooses to elongate a particular task for the purposes of irritation or general ignorance of surroundings. This keeps with a popular emerging British tradition to add man or similar as a suffix to a regular verb to form a compound word such as 'fuckboy, wasteman, roadman'.
In Lehman's terms a longman is a man/women who takes overly long at any given situation with total disregard for responsibility.
'Longman' Luke: Sup man we still meeting for 9 later?
Jack: We said 7 mate , me and James are already heading to the pub
Luke: Sorry mate Im just chilling at the moment i cant get a lift until later
Jack: Stop being a 'longman' and walk you lazy ball bag
While our lifespan is the number of years we will live, our healthspan is the number of healthy years we will have and our sexspan is is the number of years we will continue to be healthy enough to continue having an active sex life.
A lighthearted reaction upon receiving disappointing news of some sort. Usually something that isn't a particularly a big deal, esp. when it primarily affects someone else - sort of a mild schadenfreude. Sometimes doubled or tripled, and possibly said in a sing-songy voice for added comedic effect to imitate a muted trumpet, which is how the meme originated.