'xXx': Return of Xander Cage' - European Premiere - VIP ArrivalsNina Dobrev and Ruby Rose are both in Vin Diesel's new movie "xXx: Return of Xander Cage," and apparently it was not a safe set.

Nina was recently on "The Late Late Show with James Corden" and revealed that she and Ruby had a serious prank war on set, and one of those pranks involved "Taylor Swift" and left an innocent bystander bloody. It was the bystander's own fault, though, for fangirling too hard over "The Vampire Diaries" star. (It happens.)

Here's how Nina explained the prank-gone-wrong:

"We had many, many, many pranks. By the end of it we were terrified and we didn't want to leave our trailers. We were quarantined in our trailers because we thought the other one was doing something and plotting against us, and we were absolutely right because we were. And one of the ones -- Ruby is friends with Taylor [Swift], so she hired an impersonator to come to our set to sing for me and do this thing, bombard me in my trailer. What she didn't know was the girl that was hired to do this was actually a huge fan. So she got really nervous and in the middle of it ended up hitting her head and started bleeding."

Yikes. At that moment, Chris Hardwick, who was also on "The Late Late Show," quipped that the impersonator was "Taylor Not-So-Swift." Ba-dum-dum.

Watch Nina Dobrev tell the story, then see her and Chris Hardwick discuss dog vs. cat people, and also play a game of "Nuzzle Whaaa?":

Want more stuff like this? Like us on Facebook.

xXx: Return of Xander Cage Movie Poster
xXx: Return of Xander Cage
PG-132017
In Theaters on January 20, 2017

After coming out of self-imposed exile, daredevil operative Xander Cage (Vin Diesel) must race against... Read More

The Late Late Show With James Corden TV Show Poster
The Late Late Show With James Corden
CBSTV14March 23, 2015
Based on 20 critics

The English actor interviews guests and hosts musical performances. Read More