ELLEN DeGENERES remains completely embarrassed about her appearance at last year's (04) MTV Movie Awards in a Spider-Man costume - because her bottom was exposed while she was on stage.

The comedienne stepped in to appear as a phony Spider-Man as a favour to Kirsten Dunst, who claimed that Tobey Maguire, her co-star in the movie, wouldn't be able to attend.

But not only did DeGeneres discover she was lied to, she also had to endure the shame of facing crowds and cameras with her buttocks on display.

She says, "For the MTV Movie Awards, supposedly Tobey Maguire was sick and couldn't make it. So (Dunst) personally requested that I walk out there and I put on this ridiculous Spider-Man costume and Tobey walks out (in his own clothes).

"I didn't have time for a fitting, because it was the night before and I showed up... and they said, 'Well it's Spandex, it'll stretch.'

"But I couldn't wear underwear under it , because it was so tight. So I had no underwear and right before we walked out (the costume) started splitting... I know that my butt is hanging out of this thing and I couldn't see and then Tobey turns out to be okay."