75th Annual Golden Globe Awards - ArrivalsAs Margot Robbie learned, it's important to pack appropriately for every occasion while traveling.

The "I, Tonya" star recounted a hilarious story on Ellen DeGeneres' show this morning about the first time she met the host. It was during Robbie's honeymoon with husband Tom Acklerley in Tahiti.

One rainy day, the couple decided to hit the gym, but Ackerley had a pair of very, very short shorts. So much that Robbie said, "I was like, 'Babe, you cannot wear those shorts, I can see everything!" To which Acklerley responded, "Who's gonna be here?"

Well, upon walking into the gym, who was there on the treadmill but DeGeneres! And next to her was wife Portia de Rossi! And next to them ... former President Barack Obama!

"Tom's face just goes white," Robbie laughed to DeGeneres. Things only got worse when everyone took part in a stretching class!