Selena Gomez and Justin Bieber attended a sweaty pilates class together on Wednesday (03.01.18).

The 'Wolves' hitmaker and the 23-year-old heartthrob were able to enjoy the exercise, which is typically held in sweltering 95 degrees heat, in private after having a session with the owner of West Hollywood studios, Hot Pilates, on Sunset Blvd.

A source told E! News that 'Sorry' singer Justin had a ''blast'' working out with his on/off girlfriend.

It comes after the pop hunk flew into Mexico to celebrate New Year's Eve (31.12.17) with the 25-year-old beauty.

The pair reportedly met up in Cabo San Lucas - where she was partying with her pals - for some low-key celebrations watching fireworks with close friends.

A source said at the time: ''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, Justin had spent some quality time with his family in the Mexican city of Cancun.

An insider revealed: ''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.''

Selena and Justin 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.