David Titlow is a regular in Ljungby in southern Sweden.
It is his Swedish girlfriend's home town and after nine years of dating he has clocked up a number of midsummer parties, events he describes as "properly Swedish, a bit mad, but brilliant".
But the party they went to in a neighbouring village this July was different.
The couple - who live in London - took along their half-Swedish baby son Konrad and the photo Titlow snapped of the boy meeting a dog for the first time ended up winning one of the world's top photography prizes.
Judges at London's National Portrait Gallery sifted through more than 4,000 submissions from 1,793 photographers and chose 59 of them for their latest exhibition, with Titlow taking the top spot.
A former musician, Titlow was awarded a prize of £12,000 (13,925 kronor, $18,759).
"Every year all of my girlfriend's old schoolfriends have a big party at a farm building - a proper Swedish midsummer bash with all the food and crazy stuff. There is a homemade sauna and a lake and all that," he told The Local.
"As a photographer it is always a brilliant thing to go to. The light is amazing in Sweden and I find that Swedes are really open to being photographed. Brits are more conservative I think. Maybe it is just because I am 'the crazy English bloke with a camera'," he joked.
"Anyway we actually turned up in the morning after many of the gang had been up all night. People were pretty subdued but then when my girlfriend passed my son to the people on the sofa, the composition and back light was so perfect that I had to capture it...It was a magic moment that will probably only happen once in a lifetime".
Titlow said he was amused by the reaction of his modest Swedish friends and family.
"Anton, the guy in the middle is I think quite bemused that his face is now hanging in the National Portrait Gallery where there are also paintings of the Queen. But he wasn't exactly impressed, he was like 'hmmm, yeah okay cool'".
He said there had been little interest in his story from the Swedish media, but that he was "amazed" by the international response to his win, which took him by surprise.
"I was pretty shocked because they really don't let you know if you have won until the last moment. I think historically the prize hasn't had an image like mine as a winner. Some people are arguing it is too candid and not really a portrait, but I think they [the National Portrait Gallery] were making a statement and trying to use a different kind of image than in the past".
After nine years of dating a Swede, he said he would "surely" be back in Sweden for future midsummer parties.
"I love all the weird pole things and all the dances they do".