Despite that, the source claimed the stars are "hoping they might work it out," as their romance was more serious than fans knew. "They love each other very much," added the insider, noting they were "quietly" seeing each other since February.
The twosome didn't step out in public much, and though the Game of Thrones alum, 42, did attend the premiere of the 32-year-old actress' flick Ambulance in April, they walked the carpet separately.
The short-lived romance is the 42-year-old actor's first since he and ex-wife Lisa Bonet, 54, broke up in January after more than 15 years together.
"The love between us carries on, evolving in ways it wishes to be known and lived. We free each other to be who we are learning to become," they wrote in a joint statement. "Our devotion unwavering to this sacred life ... teaching our children what's possible. Living the Prayer. May Love Prevail J & L."
The duo share son Nakoa-Wolf, 13, and daughter Lola Iolani, 14.
After announcing the news, rumors spread the two were making their way back to one another, as in March, Bonet was spotted wearing her wedding ring. At the time, a Hollywood Life insider disclosed that the Aquaman star moved back into their family home.
"They are very much back together" the insider stated. "They decided to work on things rather than throw in the towel because they have so much invested in each other."
However, those reports would conflict with the alleged timeline of González and Momoa's relationship. Either way, the former spouses knew things were headed for divorce.
"Jason and Lisa were struggling in their relationship for quite some time," said an Entertainment Tonight insider. "When Jason was away filming Aquaman 2, their differences and issues were heightened. He was gone for a while and it definitely put additional stress on their relationship."