Margot Robbie has just delivered what is perhaps the most hilarious 'When I met Ellen' story ever told during her appearance on 'The Ellen Show' last week. On the other hand, it's safe to say that her husband Tom Ackerley found the whole thing less amusing.

Margot Robbie at the Critics' Choice AwardsMargot Robbie at the Critics' Choice Awards

The 'I, Tonya' star and her new husband were on a delayed honeymoon following the completion of her movie. After four days spent on a remote island in Tahiti without electricity or even mirrors, they ended the week with a stay at a luxury hotel.

It also happened to be raining when they arrived, and bearing in mind that they 'look disgusting because [they] haven't seen [their] own reflections in four days', they wanted to do something together to relax and not have to worry about themselves, and so they decided to go for a session at the nearby gym.

'We get changed to go to the gym and Tom puts on these shorts that are like his oldest gym shorts and they're tiny', Margot reveals to the audience on 'The Ellen Degeneres Show', 'They're really short and there's nothing underneath. So he gets on his bicycle to ride there and I was like, 'Whoa! Babe, you cannot wear those shorts! I can see everything!' And he was like, 'Oh, come on. Who are we gonna run into?'

After agreeing that they were unlikely to bump into anyone they knew, they continued towards the gym only to find some very unexpected work-out buddies inside. 'We walk into the gym and running on a treadmill is Ellen and then on the treadmill next to her is Portia', she continues. 

'Tom's face has just gone white and you're like, 'Hi!' and I was like, 'Oh my gosh, Ellen! So lovely to meet you'... and then you're like, 'Have you met Obama?' Standing next to them is former President Barack Obama. I'm not kidding. In a gym that is tiny.'

According to Ellen, Obama was in the area writing his new book and had been working out with Ellen and her wife Portia de Rossi for the last week. It's a shame no-one told Tom before he opted for short-shorts for a stretching class.

'It was a very confined space and we then had to do this whole stretching class but Tom meanwhile is trying to not reveal anything', Margot says. 'This gym instructor keeps saying to Tom, 'Tom, lunge! Lunge, you're not lunging!' And Tom's trying to lunge cross-legged and Obama's stepping over his legs to put his weights back. The whole thing was so absurd, it was hilarious.'

More: Margot Robbie's parents told her to get a real job

Ellen certainly agreed that his shorts were ridiculously small, and to top off all that embarrassment the host accidentally received the wrong laundry later that week; three guesses how she knew exactly whose laundry it was...