Endurance Insurance 

Horrifyingly terrible or insanely boring images used to last longer during great sex

Dude, I just saw your grandma naked. I'm going to have to use that for endurance insurance.

Endurance Insurance by enfueg013 June 17, 2012

Ensurance Beer 

The extra beer you bring to a party to ensure you will have enough to get yourself drunk.

Commonly misspelled as "insurance beer."

Guy 1: Well I've got this 12-pack for myself, but I don't know if it'll be enough
Guy 2: Grab some ensurance beer, better safe than sorry.

Ensurance Beer by skootles September 2, 2010