Tom Daley
Olympic diver Tom Daley and boyfriend Dustin Lance Black at the Dallas Cowboys Vs Jacksonville Jaguars game in November 2014Tim Whitby/Getty

Olympic diver Tom Daley has marked his second anniversary with boyfriend Dustin Lance Black by posting a sweet message on Instagram.

The 20-year-old shared the first ever selfie he took with Black, a screenwriter from Los Angeles, on the social networking site on Sunday (22 March). In addition to revealing his pet name for Black as "frog," Daley also thanked his loved one for making the last two years special.

Black, 40, returned the sentiment by writing a heartfelt message on his own Facebook page: "Two years ago we took a selfie just after meeting... the very moment my life changed forever. Happy Anniversary my love."

Before their special day, Black shared a photo from a Skype conversation with Daley, which features the British athlete making a heart shape with his hands while laying in bed. Black wrote: "Thank you @skype for making this possible. Best of luck in ‪#‎Dubai‬ tomorrow @tomdaley1994."

Daley announced their relationship in December 2013, recording a YouTube video explaining he was romantically involved with another man. Later that month, the diver sat down for an interview with talk show host Jonathan Ross, during which he said: "I'd never felt anything like it before. We were at a party and I hadn't even spoken to him all night. I didn't know what to do or if he was gay at first.

"I'd never felt the feeling of love, it happened so quickly, I was completely overwhelmed by it to the point I can't get him out of my head all the time. I've never had it before where I love someone and they love me just as much."

The couple are believed to have moved in together and are sharing a flat in London. Black is reported to have told The Sun of their relationship last year: "He's the best thing. I'm very proud. Everything Tom has said about being in love I feel and echo probably more."

2 years ago I met my ? and my life changed forever! Thank you for making these past 2 years so special ❤️

A photo posted by Tom Daley (@tomdaley1994) on