Make of it what you will.

To create this "Death self," the two performers devised a piece in which they connected their mouths and took in each other's exhaled breaths until they had used up all of the available oxygen. Seventeen minutes after the beginning of the performance they both fell to the floor unconscious, their lungs having filled with carbon dioxide. This personal piece explored the idea of an individual's ability to absorb the life of another person, exchanging and destroying it.

- Marina Abramović & Ulay
A description of one of the projects they did together in the 70s