What really caused the Demi Lovato-Wilmer Valderrama split?

Singer Demi Lovato and her boyfriend of six years Wilmer Valderrama announced their split last week via Instagram, saying they realised they were better as friends.

"This was an incredibly difficult decision for both of us, but we have realized more than anything that we are better as best friends," Lovato and Valderrama wrote. "We will always be supportive of one another. Thank you to everyone who has offered us kindness and support over the years. With only love, Wilmer & Demi."

The duo started dating shortly after Lovato turned 18, and they have seen their share of ups and downs. But this past February, Lovato revealed to Ellen DeGeneres that she was ready to walk down the aisle. When the talk show host enquired if the duo was engaged, Lovato confessed that she wouldn't mind seeing a ring on her engagement finger.

"There's a time for everything [and] we've been together this long. So I'm not going anywhere and vice versa," Lovato said, hinting that she was in the relationship for the long haul, reported People.

Was it Valderrama's hesitancy to pop the question that drove the couple apart? According to a HollywoodLife source, neither of them expressed a desire to get married or start a family. "[Demi and Wilmer] both were not in a rush to get married, they both were not in a rush to have kids and they thought that would change even when their close friends were doing all of that," a source told HollywoodLife. "But the fact that they didn't have the urge to get married and have kids really got them talking on if it was worth continuing the relationship. And that is when they realized being best friends was the best option for them."

Apparently, Lovato has already come to terms with the fact that she'll never experience the same kind of love she had with Valderrama. "They are always going to be in each others lives, but the physical love won't be there and she is OK with that!" the source added.