Jason

Derived from the name of former Southampton and Crystal Palace player Jason Puncheon.

Used to describe a person who's apparent girlfriend / boyfriend / partner is significantly more attractive than them, as in they are (Jason) punchin'.

"hey mate, check out the guy at the door, what an absolute Jason."

"Yeh shes beautiful, that guy is totally Jason."

Waiter: Check out Jason at Table 3.
Barman: There is no way she's with that guy!

Waiter: Yup, must be a drug dealer or have a massive d*#k. Coz he ugly as hell.