one more thing: https://www.welt.de/print-welt/article502130/Der-Koerper-auf-dem-Altar-der-Kunst.html

The once so strictly educated Generalstochter Marina Abramoviæ often appeared naked. Soon after her departure from the too close-knit hometown of Belgrade, she worked as a "nude" with Hermann Nitsch in 1975, the famous Viennese, who may be described as the "great grandfather of the performance". The cheerful and colorful happenings of the late 60s had to be restored to the restoration of the muff, as Nitsch and his Austrian colleague Muehl developed bloody actions, which allowed only one person in the center: the artist. Changing social conditions was no longer their intention - the Viennese took the body as a field of investigation.

Marina Abramoviæ quickly realized that while Nitsch was working with similar resources as she did, she did so for the sake of a publicly effective theatricality. Marina Abramoviæ, however, wanted to explore the boundaries of her body because she thought "the question of art is a question of life and death".

she is being quoted: "it was not my thing"

http://orf.at/stories/2368613/2368612/

Best I could find about the event: Italian source auto translated via google:

http://www.losai.eu/diabolica-follia-marina-abramovic-e-lady-gaga-arte-dellocculto/

The bizarre collaboration with Hermann Nitsch

The Marina performance is not a normal and common exhibitionism, but a paradoxical exhibitionism, mystical, in which the artist and the public itself take part in a lush, evil, obscene Sabbath of sin in which eroticism becomes a transcendental practice, a disturbing erotic-mystical covenant. His performances are deeply eschatological in which the physical body is transformed into a spiritual presence, or absence in an impressive, haunting and persistent. The artist has also worked with Hermann Nitsch in 1975 in a performance that seemed a kind of satanic ritual: lying on a wooden stretcher, naked and blindfolded, while Nitsch poured the blood of sheep on the belly and between the legs."