This is the emotional moment an Australian man broke down in tears as he asked his boyfriend's dead ex for permission to marry him.

Aussie national Stephen Chistopher could not help but cry as he promised the deceased man he will take care of his younger boyfriend Phudit just a day before their marriage.

Speaking through tears in front of the late ex's memorial in Bangkok, Thailand on July 6, a tearful Stephen said: 'You left behind a very good man and I'm gonna take care of him and make sure he's happy.

'I'm so sorry, I think you're a good man. You looked after him and you made him happy too, and I'm gonna do the same.

'We'll always remember you, and we'll always know what you did for him as well. I hope you bless our marriage and that you support us together.'

He then offered some incense after the solemn prayer to the spirit of the dead ex.

Despite having one of the most visible lesbian, gay, and bisexual communities in Asia, same-sex marriage is not legal in Thailand.

However, several bills on seeking legal recognition of same-sex couples, are waiting to go to parliament.