How does love or sex between three people come about? Just maintaining a relationship between two people can already be complicated enough. Adding just one more point to the shape that is your relationship requires the consideration of many more factors.
Unless the threesome is a combination of three strangers the relationship usually begins with a new person entering an existing group of two. Introduced in terms of a unicorn, or guest star, in our 'Threesome' article, this role is the third point, joining the couple to create the triangl