Artists Gilbert and George (Gilbert Prousch and George Passmore) pose for a photograph at the Metropolitan Arts Centre (MAC) during the opening of their new exhibition Scapegoating in Belfast, Northern Ireland, January 26, 2018. REUTERS/Clodagh Kilcoyne

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose with their artwork "Scapegoating" during the launch of their new exhibition "Scapegoating" at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (L) and British artist George Passmore, known as Gilbert & George, pose advert for their new exhibition "Scapegoating" at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (L) and British artist George Passmore, arrive for a photocall at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose with their artwork "Scapegoating" during the launch of their new exhibition "Scapegoating" at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose with their artwork "City Lights" during the launch of their new exhibition "Scapegoating" at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose with their artwork "City Lights" during the launch of their new exhibition "Scapegoating" at the White Cube gallery in Bermondsey, London July 17, 2014. REUTERS/Luke MacGregor (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose during the launch of their new exhibition "London Pictures" at a White Cube gallery in London March 8, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose during the launch of their new exhibition "London Pictures" at a White Cube gallery in London March 8, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose during the launch of their new exhibition "London Pictures" at a White Cube gallery in London March 8, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch and British artist George Passmore (R), known as Gilbert & George, pose during the launch of their new exhibition "London Pictures" at a White Cube gallery in London March 8, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert & George, pose in front of their new exhibition "London Pictures" at the White Cube gallery in London March 8, 2012. REUTERS/Stefan Wermuth (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

British artists Gilbert Proesch and George Passmore (L) pose during the world premiere of their "London Pictures" exhibition at the White Cube gallery in Hong Kong March 1, 2012. This monumental body of 292 pictures is the largest series yet created by the acclaimed British artists and 22 pictures will be shown in Hong Kong, the first venue of their global tour, according to a press release on the White Cube website. REUTERS/Bobby Yip (CHINA - Tags: SOCIETY ENTERTAINMENT)

British artists Gilbert Proesch and George Passmore (L) pose during the world premiere of their "London Pictures" exhibition at the White Cube gallery in Hong Kong March 1, 2012. This monumental body of 292 pictures is the largest series yet created by the acclaimed British artists and 22 pictures will be shown in Hong Kong, the first venue of their global tour, according to a press release on the White Cube website. REUTERS/Bobby Yip (CHINA - Tags: ENTERTAINMENT SOCIETY)

British artists Gilbert Proesch and George Passmore (L) pose during the world premiere of their "London Pictures" exhibition at the White Cube gallery in Hong Kong March 1, 2012. This monumental body of 292 pictures is the largest series yet created by the acclaimed British artists and 22 pictures will be shown in Hong Kong, the first venue of their global tour, according to a press release on the White Cube website. REUTERS/Bobby Yip (CHINA - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (L) and British artist George Passmore, known as Gilbert and George, pose in front of their new exhibition 'The Urethra Postcards' at the White Cube gallery in west London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

A detail is seen from the new exhibition 'The Urethra Postcard Pictures' by Italian artist Gilbert Proesch and British artist George Passmore, known as Gilbert and George, at the White Cube Gallery in London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (L) and British artist George Passmore, known as Gilbert and George, pose in front of their new exhibition 'The Urethra Postcard Pictures' at the White Cube Gallery in London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (L) and British artist George Passmore, known as Gilbert and George, pose in front of their new exhibition 'The Urethra Postcard Pictures' at the White Cube Gallery in London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert and George, pose in front of their new exhibition 'The Urethra Postcard Pictures' at the White Cube Gallery in London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

Italian artist Gilbert Proesch (R) and British artist George Passmore, known as Gilbert and George, pose in front of their new exhibition 'The Urethra Postcard Pictures' at the White Cube gallery in London January 12, 2011. REUTERS/Toby Melville (BRITAIN - Tags: ENTERTAINMENT SOCIETY)

A visitor views Gilbert and George work entitled "Fear" at the Tate Modern gallery in central London February 13, 2007. The artists' first major retrospective in twenty-five years was launched on Tuesday with over two hundred pictures. The show will tour extensively in Europe and America. REUTERS/Toby Melville (BRITAIN)

A visitor takes photographs of Gilbert and George works at the Tate Modern gallery in central London February 13, 2007. The artists' first major retrospective in twenty-five years was launched on Tuesday with over two hundred pictures. The show will tour extensively in Europe and America. REUTERS/Toby Melville (BRITAIN)

British artists Gilbert (L) and George (R) discuss their work in an interview at the Tate Modern gallery in central London February 13, 2007. Their first major retrospective in twenty-five years was launched on Tuesday with over two hundred pictures. The show will tour extensively in Europe and America. REUTERS/Toby Melville (BRITAIN)