Last week they got married at an informal and unofficial ceremony at a restaurant in Beijing, witnessed by around 20 friends.
The couple were spurred on by the recent US Supreme Court ruling legalising gay marriage that actually quoted Confucius: "Marriage lies at the foundation of government."
Li, on the right in the below photo, is a prominent women's rights campaigner in China and was detained earlier this year in a crackdown on social activism - during which she was not allowed to see Xu as China does not officially recognise gay marriage nor the fact they are partners.
She said that they decided to get married because they wanted "to take some action to advocate for same-sex marriage".
It's doing the impossible when you know it's impossible, but it takes those constant efforts to make changes in history."