Warthog Effect 

Any instance involving a group of females in which an 'ugly' female is kept around not for her personality, but in order to make the rest of the group seem prettier by comparison to any male interested or showing interest in the group.

Does not apply to male groups.

OMG dude, major warthog effect happening in Stacey's group with the new chick

Warthog Effect by vish1206 January 26, 2011