Demi, 27, and Mike, 31, reportedly began casually dating last month after they sparked a flirty relationship on social media while The Bachelorette's fifteenth season starring Hannah Brown was airing on ABC this past summer.
But according to multiple sources, Demi and Mike's romantic relationship has already come to an end.
"Demi and Mike's fling has fizzled out and they aren't seeing each other or texting like they were before. Nothing happened, it just ran its course," a source told E! News.
"Demi was definitely interested in Mike at one point, but it was short-lived and she wasn't ever planning on dating him seriously."
Mike, however, reportedly hopes he and Demi, a two-time Grammy nominee who previously served as a judge on Fox's The X Factor singing competition, can give their relationship another shot down the road.
"Mike hopes they can have a second chance again," the source told the website. "But for now, he's fine with being friendly."
Another insider toldUs Weekly that Mike and Demi "have pumped the brakes."
"They went on a couple of dates and texted each other every day, but it was never a serious, full-blown relationship by any means," the insider said.
"There is absolutely no love lost between them. The timing just wasn't right because they're both so busy."
It all began when Demi was watching The Bachelorette and wrote on Instagram in July, "Mike, I accept your rose," and later wrote in another post, "He always picks [Hannah] up and swings her when he hugs her. Swing me."
"I'm all about her too and she definitely was the aggressor. I find it incredibly sexy. I love that. Like, you want me, come at me. If I want you, I'm going to come at you and I'm coming at her as well."
But earlier this month, Mike awkwardly askedKeke Palmer out on a date during his live appearance on Strahan, Sara & Keke, which clearly suggested he and Demi were over or definitely not exclusive.
Keke seemed startled and caught off-guard by Mike's forwardness.
Mike then hinted to Us on October 14 he and Demi had gone their separate ways, although he was still sending "positive vibes her way."
When asked whether he plans to keep his next relationship more private, Mike reportedly told the magazine, "100 percent. Definitely."
After failing to win Hannah's heart and missing out on a hometown date, Mike was rumored to be a frontrunner to star on The Bachelor's 24th season.
Mike had a fling with Sydney Lotuaco on Bachelor in Paradise earlier this summer, but they called it quits about halfway through the season and Mike left Mexico single and wanting love.
The Bachelor position, however, ultimately went to Peter Weber, and the new season is scheduled to premiere on Monday, January 6 on ABC.