The insider claimed the singer — who filed for divorce earlier this month — "was incredibly checked out and detached" for a while before he pulled the plug on their four-year marriage.
"Joe seemed very sensitive, almost touchy, when asked anything about his wife or family-related," the source added. "So I’m guessing things were on the rocks with them before that."
As OK! reported, the two had conflicts due to their busy schedules and different lifestyles. While one source claimed the dad-of-two, 34, had enough of the 27-year-old actress' partying, another insider said the pair's dynamic was the opposite, as Jonas allegedly wasn't supportive of Turner's homebody ways after giving birth to their second daughter last year.
According to a separate source, the two were trying their best to work things out, but Jonas ultimately filed for divorce after witnessing alleged compromising footage of Turner on their Ring doorbell.
The couple confirmed their split with a joint message and insisted it was "a united decision," but other than that, the Games of Thrones star has stayed silent on the matter.
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- Sophie Turner 'Furious That She's Being Painted as a Hard-Partying Booze Hound' as Joe Jonas Divorce Turns 'Nasty'
- 'The View' Hosts Shame Joe Jonas and Sophie Turner for 'Ugly' Divorce Battle That Will Leave Daughters 'Scarred'
Meanwhile, the "Sucker" crooner has been on tour with his two brothers, where he's vaguely discussed the drama.
“It’s been a tough week. Thank you everyone for your love and support. Me and my family love you guys," he told the crowd at the Jonas Brothers' September 9 concert.
"I just wanna say, look: if you don’t hear it from these lips, don’t believe it. OK?" he added of the ongoing rumors.
At one performance, Jonas shed a tear while singing "Hesitate," a tune he penned in his estranged spouse's honor.
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At the moment, the pair's two daughters are under Jonas' watch as he tours, as he reportedly has more resources and help available. The British beauty was overseas filming a movie, which she appeared to have a wrap party for in England on September 3.
Page Six reported on Jonas being detached from the marriage.