Brotherly love will be forgotten on Saturday when Germany's Jerome Boateng faces his sibling once more at a World Cup with Ghana's Kevin-Prince Boateng predicting a 'fight to the death'.
The half brothers were both born in Berlin to separate mothers, but in 2009, Schalke's Kevin-Prince, 27, opted to play for the country of his father.
He turned to Ghana having become discouraged by a perceived lack of opportunities even after the brothers had made a single appearance in the same Germany Under-21 team.
The brothers normally have daily contact via SMS or telephone, but there has been radio silence as they prepare for the Fortaleza clash in Group G.
"We've had no contact recently, each of us is just concentrating on himself," said Bayern Munich's Jerome Boateng.
The 25-year-old will face Ghana with a splint on his right hand having torn a thumb ligament in Germany's opening 4-0 win over Portugal.
This is not the first time the brothers have played each other at a World Cup.
In South Africa, they set a record by becoming the first brothers to play against each other at a World Cup finals.
A nervous Germany needed Mesut Ozil's second-half goal to seal a 1-0 win over Ghana in Johannesburg after a shock defeat to Serbia as both sides reached the knock stages.
Four years on, Germany are looking to maintain their grip on the group after hammering Portugal, but Kevin-Prince has turned up the heat on the tie.
"It's like in ancient Rome. There will be people around the pitch who want to see how two teams fight," the Schalke 04 star told German magazine Sport Bild.
"The team who wants it more will win and we will fight to the death against Germany."
There was bad blood between the brothers before the last World Cup when a hard Kevin-Prince Boateng tackle in the FA Cup final between Portsmouth and Chelsea ruled Germany captain Michael Ballack out of the tournament.
"At the time we certainly had a few arguments," revealed Kevin-Prince.
The brothers hail from the tough Berlin district of Wedding and neither are short of confidence, but Kevin-Prince attracts attention.
As a seven-year-old, he successfully played a game for a place in Hertha Berlin's young section in rubber Wellington boots as they were his favourite shoes at the time.
And in an interview with German football magazine 11Freunde, Boateng was once happy to admit: "Yes, I am the best footballer in the world".
After spells at Tottenham Hotspur and AC Milan, the heavily-tattooed Kevin-Prince has tried to shake off his bay-boy image and has become a father.
He had to be content with an appearance off the bench in his side's 2-1 defeat to the United States on Monday.
In contrast, Germany coach Joachim Loew singled out Jerome for praise after keeping World Player of the Year Cristiano Ronaldo subdued as Thomas Mueller claimed a hat-trick against Portugal.
Whatever the outcome of Saturday, there will be at least one happy member of the Boateng clan.
"For me, it's the easiest game ever," Prince Boateng told German daily TZ.
"Regardless of what happens, I can only win. My only wish is that nobody gets hurt."