Margot Robbie ''definitely can't'' reveal the antics of the 'Suicide Squad' cast.

The 27-year-old actress appeared on BBC Radio 1 with Nick Grimshaw, taking part in 'The Heart Rate Monitor Challenge', where her pulsating heartbeat was monitored as she responded to a series of embarrassing stories from famous co-stars.

Margot squirmed in the make-shift doctor's chair as her 'Suicide Squad' co-star Cara Delevingne brought up trigger words of their past experiences together.

At the mention of the Ginuwine song 'Pony', the actress burst into fits of laughter as her heart rate spiked to 133 beats per minute.

However, the Australian beauty admitted that she is sworn to secrecy over the mysterious moment Cara was referring to, and she didn't want to spill the gossip.

Margot said: ''I definitely can't say. I can't talk about any of this stuff.

''I would just say it's a few things that happened when we were shooting 'Suicide Squad'. Some real experiences!''

The blonde beauty did admit that the cast of the DC Comics film had a ''wild time'' on set, although she didn't elaborate any more on the memories.

Margot insisted: ''What happens in Vegas stays in Vegas. It was a wild time, though.''

Shockingly, the thing that raised the actress' heartbeat the most was when Nick showed her a video of the special song dedicated to her by one of her favourite childhood bands, Bullet For My Valentine, to a crowd of 15,000 people that he had lined up for her.

Covering her mouth in shock, she couldn't contain her excitement, saying: ''You are f***ing kidding me. I'm dying, this is like my whole childhood.''

When the song ended, Margot told Nick he was her ''favourite person in the world'', admitting that she was ''honestly so touched'' that he had arranged the special surprise for her.

She said: ''Oh my god I can't believe this has happened, what a great morning. I mean, I'm half having a heart attack but thank you!''