Blake Shelton and Gwen Stefani have decided to take some time apart -- a big move that could make or break their relationship.

According to a report by Radar Online, sources said that the decision could spell tension between the couple. 

A Trial n The Relationship

The couple started dating in 2015, but their time apart is already causing issues in their five-year relationship.

Blake Shelton is currently on an official tour for "Friends and Heroes," while Gwen Stefani has been focused on her "Just a Girl" residency in Las Vegas. 

"This has been the first time in a long while that the couple will be spending time apart for this long," Radar's source revealed. "Blake falls into pieces without Gwen by his side.

Moreover, the same source said that people close to them are wondering if they can overcome the challenge of being separated for a long time.

"It's the longest they will be apart in years and the strain in their relationship is already showing. A lot of people around them wonder if their love can stand the test of time."

It has also been revealed that the couple believes the distance will only bring them closer together. They will be apart for months due to work, but they have complete faith that, as the old adage goes, "distance will make the heart grow fonder."

According to her friends, the "No Doubt" singer leaned on Blake for emotional support, especially during the beginning of their relationship. Blake was there to help her get through her divorce from ex-husband Gavin Rossdale. The country singer was also there for Gwen's three kids -- Kingston, 13, Zuma, 11, and Apollo, 5. 

A Shift In Dynamics

However, things have taken a great shift over the years in their relationship.

"The dynamics between them is shifting. In the beginning, Gwen was the dependent one. Now, Blake seems like a lost soul who has to know where she is every second of the day," the Radar source revealed. 

The couple has rarely been apart, with Blake and Gwen allegedly spending "every waking hour together." Moreover, according to the insider, the last few years of their relationship has made Blake very dependent on Gwen for practically everything. 

"Truth be told, Gwen is also looking forward for a little break," added the source. Apparently, the "Don't Speak" artist wants some "me time" and spend some time with her friends. 

According to the National Enquirer, the couple has been fighting over a myriad of things, including the final design for their new mansion in Los Angeles. They are also fighting about the delays in their formal wedding ceremony until the Catholic Church grants Gwen an annulment from Gavin. 

Sadly, their friend thinks that physical separation might only strain the relationship even more.  It might push their relationship too hard to a point where the couple could breakup. 

A source close to the couple believes that this could be their biggest test yet. Should their fans worry at all? Gwen Stefani and Blake Shelton will not be together for quite a while for work, and fans can only hope it helps keep their burning desire to be together stronger than ever. 

READ MORE: Blake Shelton Ready to Take Relationship With Gwen Stefani to The Next Level -- Here's the Proof!