The temperamental pair, whose explosive fights were documented on their E! reality show, Rob & Chyna, aren't having a screaming match over their split this time, the source says.
"This breakup feels more real because both of them are very calm," the source tells Us.
As Us Weekly previously reported, the pair, who share 3-month-old daughter Dream, have been on the rocks since their big blowout at Christmastime, when the Lashed Bar owner, 28, moved out of the house they shared, clearing out the nursery and taking their daughter.
At the time, they both posted about the turmoil on social media, with the Arthur George sock entrepreneur sharing several emotional Snapchat videos. This time around, they are being conspicuously silent on Instagram and Snapchat.
"Rob and Chyna haven't really been together since Christmas, not really properly," the source adds.
The pair, who got engaged last April, just two months after they began dating, are now living separately. Chyna is back in her home and Kardashian, 29, has been staying at the Calabasas, California, estate that his mom, Kris Jenner, bought for $2.3 million last February.
"They are looking forward to coparenting," says the source, who adds that the pair haven't talked a lot about the details but are both being "very responsible" about making their daughter a priority.
The couple had heated arguments in the past, mostly triggered by jealousy. "In a romantic relationship, Rob doesn't trust Chyna at all," the source tells Us. "They both had major trust issues, and they grew apart."
Chyna was also spotted having dinner with a man named Jamel Davenport in West Hollywood last week, but another insider previously told Us that their relationship is not romantic.
"The fighting is over for now," the source says. "Rob's family isn't happy or sad about it; they just want Rob to be happy and that relationship wasn't making either of them happy anymore. Rob and Chyna know and understand that they aren't meant to be together."
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