Cape Town - Scrumhalf Faf de Klerk admitted to being "massively surprised" by the reaction to the South African speedo he wore following the Springboks' Rugby World Cup win in Japan early last month.
De Klerk, 28, made waves around the world after the Webb Ellis Cup-clinching victory over England in Yokohama when he stripped down to his undies in the change room after the match.
De Klerk even wore the speedo for the official celebration photoshoot, while he also met the Duke of Sussex, Prince Harry, while wearing the briefs.
At Cape Town's City Hall while on the team's Champions Tour of the country, De Klerk even gave Archbishop Desmond Tutu a glimpse of his Speedo.
De Klerk's actions spawned the which, according to News24, is an undertaking to get men to check their "crown jewels" for signs of testicular cancer.
Springbok skipper Siya Kolisi - as well as several Bok team-mates - added their support to the 'challenge' soon thereafter.
On Thursday, De Klerk managed to persuade star England duo Chris Ashton and Danny Care to parade around in a pair of South Africa flag undies during a podcast on the BBC website where they discussed winning (or losing) the World Cup, boozy celebrations, the secret to beating England and life in Manchester.
Neither Ashton (44 Tests) nor Care (84 Tests) were part of England's World Cup squad.