The on-off couple, who spent Christmas apart with their respective families, posed with a female fan separately after arriving in Mexico, reported Ace Showbiz.
"Time for a little relaxation. Chilling with friends on vacation," he posted on Twitter.
Bieber, 18, later posted pictures of his shirtless self hanging out in a sunny place with exotic trees in the background.
The Canadian pop star also gave a look at his new tattoo in two other pictures. It's a picture of Jesus before praying hands were added and flowers were recently etched around the bottom.
Before Christmas, Bieber and his girlfriend joined Taylor Swift and Harry Styles hitting the slopes in Utah. After the double date, they went their separate ways with him flying back to his home country of Canada and her returning to Los Angeles.