Ain't Nothing But a Horn Dog

10/28/2008 5:26 AM PDT BY TMZ STAFF
The concept of a live-in ex girlfriend may sound as implausible as Clay Aiken impregnating a woman -- oh, wait -- but deviled Hugh Hefner and Holly "Elvis with breasts" Madison seem to be getting along just fine.

Hef, Holly and the other girl next door, Bridget, shared the same air at the Playboy Mansion Halloween party this weekend.