Lucy Mecklenburgh scolded her boyfriend Louis Smith for posting a picture of their bare bottoms on Instagram.

Lucy Mecklenburgh and Louis Smith (c) Instagram

Lucy Mecklenburgh and Louis Smith (c) Instagram

The former 'The Only Way Is Essex' star has revealed she did not give the Olympic gymnast permission to publish the photograph and was mortified when she saw it online.

Lucy explained: "He didn't tell me he was going to post it. We took the photo after the BAFTAs in the hotel. We'd just got back and we'd had a couple of drinks and we were just messing around. I didn't know he was going to post it the next day. But he's quite like that."

The 23-year-old beauty - who was previously engaged to her 'TOWIE' co-star Mario Falcone - claims both she and her publicist gave Louis, 26, a stern telling off for posting the cheeky snap.

She told the Daily Mirror newspaper: "Louis got in trouble for that. By both of us."

Louis took to Instagram after the British Academy Television Awards to quiz his fans on who they think has a nicer bum between him and his fitness fanatic girlfriend.

Captioning the photo, he wrote: "Who has the better derrière? Me or @lucymeck1 haha #battleofthebutts. (sic)"

Lucy is now working on a plan to get revenge on her hunky boyfriend, whom she got together with late last year after first meeting on the set of the BBC show 'Tumble'.

She added: "I'm going to get him back though, don't worry, I'm working on it."