Justin Bieber and Selena Gomez's relationship is heating up and according to a new report, Bieber is doing everything he can to prove that he is a changed man to his on-again, off-again girlfriend.

About one month into their relationship, an insider claims Bieber has undergone quite a lot of change in recent months and simply isn't the same guy who reportedly cheated on Gomez numerous times during their relationship years ago. 

“Justin has gone through a complete metamorphosis since he and Selena last dated,” a source explained to Hollywood Life on Nov. 26. “He’s determined to show Selena, her friends and family that he isn’t that guy now. He’s done a lot of growing up in the past couple years and it shows."

The insider went on to say that Bieber is incredibly loving and focused. He wants to show everyone this new side of himself.

Gomez and Bieber began dating in 2010 and remained committed to their relationship until two years later. Then, for several years, they dated on and off as Bieber also kept company with a number of other ladies, including model Hailey Baldwin, Keeping Up With the Kardashians star Kourtney Kardashian, actress Nicola Peltz, and socialite Sofia Richie.

While Bieber is reportedly a new man now, Gomez's family is a bit concerned about how she may be impacted by their relationship, but are allegedly doing what they can to stay positive. As another report revealed, Gomez is said to be happier now that she and Bieber are back together and her family is trying to be supportive of their new romance.

“As much as people around her are worried that she’ll end up heartbroken all over again, it’s hard not to be happy for her,” the second source revealed to Hollywood Life. “She tried her best to put things with him behind her and for a long time it seemed like she had. But it’s obvious now that she was carrying a heavy weight around with her this whole time. Now that she’s back with Justin that weight has lifted, she just seems very light and joyful.”

Gomez and Bieber have been seen together on numerous occasions since first being caught together at Gomez's Studio City home at the end of October.