With their arms around each other, Josh and Diane were pictured in New York City on Feb. 12 attending the opening night of Second Stage Theatre's "Smart People," in which Josh stars.
Thursday night's event marked the first time the couple was photographed together since early November when they attended LACMA's Art+Film Gala. That November event was only a month prior to the reports that Diane had cheated on Josh with "The Walking Dead" star Norman Reedus at a dive bar in New York City.
Diane and Josh have been together since 2006. The couple was hit with rumors that they had split in January, as well.
The December report by the New York Daily News said that Diane and Norman were at a back table "wildly making out" at an East Village watering hole on Dec. 12 around 1:30 am.
"They were laughing and having fun and then she just literally got out of her chair and straddled him and we were all like, 'what the hell,'" an onlooker to the Daily News. "They were all over each other. She was a lot more aggressive than him."
Another witness told the Daily News, "they were making out on top of each other, holding hands."
Diane, as well as Joshua, starred in the 2015 film "Sky" with Norman.
Over the course of their relationship, Joshua and Diane appear to be the picture of happiness, as they are often photographed gazing into each other's eyes. Marriage doesn't seem to be in their sights, but that hasn't seemed to be an issue.
Since 2006 they had successfully avoided any major drama until last December's cheating report.
At the time, a rep for Norman denied the incident and Diane's rep declined to even respond.
A source close to Diane and Josh told The Daily Mail, "This story is completely fabricated and untrue."
In November, Joshua told People magazine that the secret to the longevity of he and Diane's relationship is that they, "work at it."
"I mean it's so banal. It's not always easy because nothing in life that's worth doing is always easy," he added. "I understand at 37 better than I ever did at any other time in my life what the phrase like, 'Love's labor' really means. It's work. But it's work that rewards itself many times over."