Adds one insider: "They broke up shortly before her birthday, then got back together."
(When reached for comment, a rep for Jonas had no comment.)
Indeed, Jonas organized Greene's 24th birthday blowout at West Hollywood's STK on Feb. 18. "He wanted to make sure everything was perfect," another insider told Us at the time. "He was really sweet and conscientious."
"She really puts my feelings first. She understands my busy schedule," he said of the sexy star, whom he visited in January on the Baton Rouge, La. set of Breaking Dawn. He even met her parents in Jacksonville, Fla. "Her dad can drink me to shame," he joked. "He's awesome."