It was supposed to be just another day of press in her native Australia for Margot Robbie. While sitting alongside her Peter Rabbit co-star Elizabeth Debicki and waiting for an interview with MTV Australia to start, her little brother, Cameron, walked in.

It was obviously a huge surprise, because the 27-year-old actress exclaimed, “Oh my god!” when her brother sat down in front of her. 

“Excuse me, can you calm down?” Cameron quipped. “We’re in an interview.” 

Robbie’s delight quickly turned to trepidation when the topic of pranks came up. Perhaps big sis was a bit of a prankster growing up?

Watch the moment unfold below.