Brian Austin Green says he forgot he had sex with 90210 co-star in awkward admission

Brian Austin Green has said he forgot having sex with his 90210 co-star in a rather awkward chat.

Green, 51, sat down with Tori Spelling - who played Donna Martin in the Beverly Hills show - where they reminisced about their time together, both on and off screen.

Discussing their relationship on Spelling's podcast, misSPELLING, Green called their time together 'much more' than boyfriend and girlfriend.

“That label of, like, oh, boyfriend girlfriend, are you dating? That almost felt disrespectful to me because it’s like, no, we went through way more than just what normal people go through when they’re dating,” he said.

“Like, oh, we dated, and then we broke up - we never did anything, we never broke up. We never said, ‘it’s just you and me, let’s try’.

“There were never any boundaries or rules or anything set to it because it showed itself in so many different ways.”

The pair also spoke about the first time they had sex, although Green admitted he couldn't remember that particular occasion.

Spelling explained they'd spent the day together at Disneyland, but ended up arguing the whole time.

“I was like, ‘Why are you always getting mad? Why are you why are we always fighting?’” she said. “And you said, ‘Have you ever thought that maybe I fight with you because I love you?’"

Spelling continued: “Yeah, and you were probably saying ‘I love you’ like we’re sister, brother, like, friends... And I was like, ‘He said I love you’. And then we started kissing.”

Green interrupted: “Wait, what? I love this story. I feel I’m hearing a story of you and someone else right now.”

Spelling then reminded Green that they went back to the hotel room and ended up sleeping together.

The next day, Spelling told co-star Jennie Garth.

“She was the first person I was like, ‘You’re not gonna believe what happened, Brian and I slept together’,” Spelling added.

Despite not remembering, Green said: “I remember other times, but I do not remember that time at all. I don’t know how that’s possible.”

Green was previously married to actor Megan Fox, after the pair met while shooting Hope & Faith back in 2004.

Two years into marriage they welcomed their first son together, Noah, now 12, followed by Bodhi, now 10 and Journey, now aged eight.

Speaking to Spelling about the end of their marriage, Green said: "She’d gotten to the point where things weren’t great, so I think everything was annoying her.

“You kind of get to the point where you’re like, ‘God, just the way you’re shuffling your feet right now. The way you’re putting that toast in the toaster’s just driving me crazy' - it’s all that stupid little stuff.

"That to me is when you either have to make the choice to say, ‘Okay, we’re going to go into therapy, and we’re gonna try to find our connection and figure out what’s going on now, or these things are going to sink us'.

"They’re going to be the death of us, because they just build up, and build up, and get worse, and worse.”