Justin Bieber and Selena Gomez may have split four years ago but they can't get away from each other completely. Last week, Biebs quit Instagram after that controversial spat with his ex who tried to defend his fans who feast on his picture with rumored girlfriend, Sofia Richie. Despite the spat, the songstress apologized and even thought that Biebs is still her soulmate.

"Selena wants to do whatever she can to cut her attachment to Justin. It's difficult because she can't understand why it's been so easy for him to move on and so hard for her," says a source.

The Kill Them With Kindness songstress had previously tried her luck in dating (e.g. Samuel Krost, Charlie Puth or DJ Zedd) but seems to have a hard time finding her happy ending.

"She's sworn a million times that she would just let it all go but dating other guys has been a little challenging. The problem is that she believed for so long that Justin was her soul mate, so she can't seem to shake it."

Last week's Instagram spat had been messy with the singer accusing her ex of cheating on her multiple times while they were still in a relationship.  The Canadian hitmaker, meanwhile, hit back at her, saying that she is just using him for attention until finally, he quit Instagram.

"I'm gonna make my Instagram private if you guys don't stop the hate this is getting out of hand. If you guys are really fans you wouldn't be so mean to people that I like," he wrote to his 77 million followers.

It did not take long for the Same Old Love singer, however, to recede from the nasty exchange of words airing her apologies calling her comments as 'selfish and pointless.'

Meanwhile, even without his Instagram, sources continue to follow Biebs with latest photos showing that the pop sensation is having a cozy, romantic embrace with Sofia Richie (daughter of the legend Lionel Richie and reality TV star Nicole Richie) at the Tokyo's Ueno Park.