Conor McGregor brutally trolls Harry Styles over colourful outfit as One Direction star shows off chest at Grammy Awards

CONOR McGREGOR brutally compared Harry Styles' colourful Grammy Awards outfit to a wrestling singlet.

The One Direction star showed off his chest in a custom made jumpsuit on the celebrity red carpet in Los Angeles.

McGregor chimed in on the fashion statement after a Twitter user asked: "What is the first thought that enters your mind when you see this?"

The UFC legend replied: "Freestyle wrestling haha."

Contestants in the Olympic sport are required to wear sleeveless singlets.

Styles, 29, has wowed with his daring outfits before, paying homage to greats like Elvis Presley, Freddie Mercury and Mick Jagger.

McGregor, 34, is a sharp dresser himself, known to show off suave suits and his expensive watches.

The Irishman is set to make his UFC return in September against Michael Chandler.

They will also coach against each other on The Ultimate Fighter, a series where contenders fight for a UFC contract.

Season finalists then meet in a finale, while coaches McGregor and Chandler go on to headline themselves.

McGregor stars on The Ultimate Fighter for the second time, following his 2015 appearance against Urijah Faber.

And UFC boss White confirmed his return to both the series and the octagon.

He said: "We just confirmed the coaches for season 31 of The Ultimate Fighter.

"Conor McGregor and Michael Chandler will go head-to-head as coaches of The Ultimate Fighter. 

"Team McGregor versus Team Chandler. This season premieres Tuesday May 30 and runs through Tuesday August 15 on ESPN and ESPN+. 

"Then at the end of the season McGregor and chandler will fight live on ESPN+ PPV and I do not have a date or location for that but we will announce it soon."