A film by a gay man whose partner died before they could legally marry and his plea for marriage equality on the anniversary of the accident which took his life has been viewed half a million times in three days.

Shane Crone’s unflinching film highlights the lack of rights for gay couples barred from legally-recognised unions and the superiority of family rights to the deceased’s estate when tragedy strikes.

Crone and his partner Tom Bridegroom had been together for six years. Where Crone’s family had accepted their relationship, the film says, Bridegroom’s parents threatened him and told him they should have sought treatment for his homosexuality.

Bridegroom died in May 2011, falling from a rooftop. The couple had been engaged to marry when California would legally recognise their union.

Having returned with his body to Indiana, Bridegroom’s family cut off contact with Crone and barred him from his partner’s funeral with threats of violence.

As the film says: “Had Tom and I been legally married, many things would have been different. Losing a loved one is devastating enough, but to then be rendered legally insignificant only makes the pain worse.”

Crone said: “I need to fight for what’s right. I need to fight for what I believe in and I can’t just stand back any more. Maybe that’s why this all happened, maybe this is part of the reason, to open my eyes and inspire me to want to make a change and fight for equality.

“I just don’t know if people will listen. I guess no one’s going to listen if I don’t talk. So I’m talking.”

The film was released days before North Carolina voters approved a constitutional amendment to ban marriages and domestic partnerships for gay couples.