The 'Nothing Compares 2 U' hitmaker – who has had an on-off relationship with Barry Herridge since their marriage in December – thinks her spouse is "completely and utterly nuts" and so obsessed with death, he thinks he will pass away in three years.
She said: "He's a very unusual character. We call him Wednesday, out of 'The Addams Family.'
"He has this mad thing where he's convinced he's going to die in three years. I keep laughing. He asked me to marry him on the first date. He said, 'Because I'll need you to do this, that, with my ashes.' We're working out the funeral every day. He's completely and utterly nuts in a very safe way. I'm having a great time."
More stories on Sinead O'Connor
Robert Pattinson and Kristen Stewart spotted at pre-Oscar bash
The Irish singer has had three previous marriages, and she admits she was initially reluctant to walk down the aisle again.
She told The Word magazine: "I had an enormous aversion to marrying again but he changed my mind. I dunno, ask Rod Stewart. No one seems to mind when it's fellas. It's like the four kids with four different men thing. F**k off. Men can have babies whenever the f**k they like and nobody says a word."