Bieber, 21, who was in Las Vegas over the weekend to watch the Floyd Mayweather, Jr vs Andre Berto boxing match, approached Susie Melendez and her friends when they were celebrating her upcoming wedding at the pool, reported Aceshowbiz.
Melendez, took to Instagram to share a picture of her with the "What Do You Mean?" singer.
"The Biebs came to party with us too!" she captioned the photo.
Bieber, was spotted wearing a white ganji and a fedora hat.