vagina sisters 

Close friends who have had sex with the same boy. Like vagina cousins, but more important.

Kerri and Christina are the best vagina sisters out there.

vagina sisters by kbearbabyyyy November 24, 2010

Vagina Sisters 

Two friends that are so close their menstrual cycles become in sync.

Girl 1: "Stephanie has been hanging around Erica a lot lately.. You don't think they're vagina sisters yet... do you?"
Girl 2: "I can't tell.. But I think I'd have to say so."

Vagina Sisters by Kawaiikittypop September 11, 2014

Vagina Sisters 

Two friends who are so close their menstrual cycles are in sync.

Girl 1: "Stephanie sure has been hanging around Erica a lot.. Do you think they're vagina sisters yet?"
Girl 2: "I'm not sure but I'd have to say so.."

Vagina Sisters by Kawaiikittypop September 11, 2014

Haven's Sister's Vagina 

A dark hole from which your penis cannot escape from and will never be seen again.

The pit from the movie "Army Of Darkness" before Bruce Campell fell in pretty much sums up Haven's Sister's Vagina

Haven's Sister's Vagina by Efren The Retarded Rabbit October 18, 2009