Sean made the revelation as he was talking to BBC Radio 6 Music host Chris Hawkins about what he learned putting together the box set for his dad's 1973 album, Mind Games, which was released earlier this year.
He added, "You look at the album cover [of Mind Games], it's a collage of my mum literally the size of a mountain, and he's this little tiny thing sort of fading into the background. And I think it's clear what his view of my mum was in his life."