Two Sacker 

A female having an appearance of such hideous nature that not one, but two sacks are required to facilitate consensual intercourse between the female and a second party. The sacks are referred to formally as the principal and secondary sacks. The principal sack is placed over the head of the aforementioned female and serves as precautionary measure in the prevention of unnecessary visual exposure by the second party. Such visual exposures have previously been observed to cause severe gastric disturbances resulting in projectile fluid discharge--not to be confused with sexual lubricants (unsuitable viscosity). The secondary sack, more commonly known as the "safety net" is placed over the second parties head as a means of N+1 redundancy. Thus, should the principle sack fail (i.e., become banged off), the secondary sack shall become the primary means of visual protection. It should be well noted that neither sack is intended nor capable of preventing pregnancy or STDs.

Sam: Dude, I accidentally banged the principle sack straight off this two sacker the other day.

Nick: Holy shit. Dude you gotta be more careful.

Sam: Yea man, good thing I had my secondary sack stapled to my forehead.

Nick: Thank god for the N+1 rule.

Two Sacker by threeleggeddog July 13, 2012

Twobacker 

A girl whose breats are very small. The overall appearance is one of a person who posses two backs on the upper torso.

Hey check that chick out over there she is stunning, shame she is a twobacker.

Hey dude I felt like a necrophiliac when I was doing Sarah last night she was all ribs, a real twobacker

Twobacker by Mp900rr July 18, 2009