Washington, May 15 : Shia LaBeouf has for the first time revealed intimate details of how he ruined his first sexual encounter by pretending to be a know-it-all playboy.

In a candid chat with the new Playboy magazine, the `Transformers' star confessed that he lost his virginity four years ago, at the age of 18, and the big night turned out to be a huge mess-full of bad lines and embarrassment.

"For some reason, I was trying to portray myself as a man who had done it (had sex) many times in the past. I didn''t tell the girl I was a virgin," Contactmusic quoted him as saying.

He added: "I was all, ''Don''t worry, babe. I''m gonna handle it tonight.'' And meanwhile I was shaking in my boots."

The 22-year-old star admitted that his first sex encounter took place in a hotel in Montreal, Canada.

"Getting naked was very strange. It was the first time I''d been naked in the light, in front of a girl, with no hiding place," he said.

"It became apparent pretty quickly that I didn''t know what the f**k I was doing. Somewhere in her mind she had to know.

"I remember laying her on the bed and putting a pillow underneath her because I had seen that in a porn movie... (It) put her at a weird angle, where I couldn''t get in correctly. I''m not extremely well-endowed... and clearly this wasn''t the move to do," he added.

However, the embarrassing night did have one upside-the girl in question became a long-time girlfriend even helped LaBeouf become a much better lover.

He added: "We had time to work it out. We had a lot of sex and would read the Kama Sutra together and do the wildest s**t." (ANI)