It’s black and white, very grainy, and starts out with someone sitting in a rocking chair in a worn-down old house. Then something sexual happens (I don’t remember what exactly), and I remember someone or something emerges from the person in the chair. I realize it’s not a good description. I think it was made in the last 10-15 years and makes Jodorowsky look like John Hughes. It’s REALLY weird.
Sounds like you probably saw a clip from the opening of Begotten.