Sources said it was a "mutual decision" and that Nina was devastated.

How's Nina Dobrev doing amid her breakup with Shaun White, you ask? The Vampire Diaries actor was spotted chilling on a yacht vacation with Zac Efron (love that for her) just a week after news of the split broke. And before you start jumping to conclusions, FYI that this was a friend vacation -- the pair were also joined by Chace Crawford and his girlfriend Kelsey Merritt, as well as Miles Teller and Keleigh Sperry.

Keleigh shared a pic of the group (see below) -- but also the Daily Mail has pics of Nina and Zac...in case you're curious!

As a reminder, news broke on September 11 that Nina and Shaun called off their engagement after five years together. A source told People that "It was a mutual decision and wasn't an easy one, but it was made with love and a deep respect for one another."

They were seen holding hands just a few days before the split, so cheating rumors popped up pretty quickly -- and were swiftly denied by sources!

Per an Us Weekly insider, "Nina is devastated. They had finally started planning the wedding and things were in motion." They added, "There was no cheating at all during the course of their five-and-a-half-year relationship. They were very loyal to each other. Any online speculation that suggests otherwise is ridiculous."