Justin Bieber flew into Mexico to celebrate new year with Selena Gomez.

Justin Bieber

Justin Bieber

The on/off couple reportedly saw in 2018 together after meeting up in Cabo San Lucas on Sunday night (31.12.17) - where she was partying with her pals - for some low-key celebrations watching fireworks with close friends.

A source said: "He and Selena spent time together again. They were very low-key and dressed casually.

"They rang in the New Year together and enjoyed watching fireworks over the ocean."

Another source added: "Justin had a great new year's Eve with Selena. He is looking forward to 2018 with her.

"It was a special evening shared with a few close friends in a beautiful place."

Days before reuniting with Selena, 25, Justin, 23, had spent some quality time with his family in the Mexican city of Cancun.

An insider told E!: "Justin flew in to Cabo on a private jet from Cancun where he spent a few days with his family.

"He arrived on Saturday evening and checked into an ocean-front villa 10 minutes away from Selena's villa where she was staying."

Selena jetted out to Cabo from Los Angeles on Boxing Day (26.12.17) on a private plane with her girl pals, but there was no sign of Justin at the time.

A source said: "She seemed very excited when she landed and was giggling with her friends and taking photos.

"They are all planning to do some fun dinners and spend New Year's Eve together."

The 'Never Say Never' hitmaker and the 'Wolves' singer rekindled their romance over a month ago, just weeks after she split from her boyfriend The Weeknd.

Justin reached out to Selena last year after she underwent a life-saving kidney transplant.