KM / Fame Flynet 1 / 10
KM / Fame Flynet 1 / 10

So there really was something between David Silver and Donna Martin in real life! (Breathe, breathe…)

Tori Spelling, who played the at-times innocent Donna Martin on "Beverly Hills 90210," revealed that she and Brian Austin Green actually had sex during their faux days at West Beverly Hills High School. Not only that, but there was another costar who she did the hanky panky with, too, but she won't say which one.

Tori reveled her sex secret during a new sneak peek from Lifetime's upcoming one-hour event "Tori Spelling: Celebrity Lie Detector" -- premiering after their latest flick, "The Unauthorized Beverly Hills 90210 Story."

After saying she slept with Brian, she said she was getting the "chills" while talking about him.

"I was a young girl," she said. "Brian and I were the youngest. We were 16, and I remember the first time I shook his hand, I had that ... I fancied him," she said, admitting that she had feelings for him at the time. She was also self conscious because of the attractive extras on the set.

"He would tease me. He teased me a lot. He would always come up to me and say that I had peach fuzz right here," she said, touching her high cheek bones. "He would come up and pull on my peach fuzz and he would be like, 'Oh my God, you're like my little lamb chop…' There are all these hot girls, and I'm hoping he likes me." On the show, Tori and David's characters dated on and off throughout the series.

As a part of the lie detector test, host Louise Roe asked if there were any other costars who she slept with. "Yes," she admitted, "but I'm not going to tell you who it is."

A visibly shaken Tori said she's never spoken about the other man in her 90210 love triangle, but she said it wasn't Ian Ziering. As Louise pressed, Tori donned a poker face, refusing to give up whether it was Luke Perry and Jason Priestley.

"Half my friends don't even know this," she said.

So, when it comes to high school and womanhood -- "Donna Martin graduates!"