Mannheim, 18, posted a photo from the music festival sitting in the grass while Ren, 22, sat next to him, leaning onto his leg.
"bet you have no idea where we are," Manheim joked in the caption.
In another photo shared to his Instagram Story, Manheim and Ren walk while holding hands and looking into the distance.
Fans took to the comments section wondering aloud if the stars were together.
"Is it wrong for me to ship you two?" one Instagram user asked.
"Are they dating?" another asked.
"I WANT THEM TO DATE," someone else wrote.
Other fans were convinced that Ren and Sierra Burgess Is a Loser actor Noah Centineo are together.
"[Oh my God] this is torture I wish they both could just date but nahhhh Noah exists. THEY LOOK SO DAMN CUTE TOGETHER," one fan wrote.
Manheim has shared regular photos with Ren ever since they met on season 27 of Dancing With the Stars in 2018. One recent photo shared from March shows him and Ren relaxing together. "You ever realize you're gonna miss the moment while [your] living it?" he captioned the cozy photo.
One photo shared soon after the DWTS finals, which both Manheim and Ren competed in with respective pro dance partners Witney Carson and Alan Bersten, Manheim shared a photo of Ren laying her head in his lap and looking up at him.
"The other snack that smiles back," he captioned the photo, which drew a lot of attention from fans, who at the time were convinced Ren and Bersten were together. Ren also shared the photo on her own Instagram feed, writing an equally playful caption: "is this seat taken?"
Earlier this month, Bersten admitted that his relationship with Ren, which was heavily teased by Dancing With the Stars throughout the season, "didn't end up so well."
"We met on the show, and you know, that is her whole career … she is a social media influencer, how could I tell her whether she should post something or not? You know, that's not my duty as a boyfriend. I personally am a super private person," he said.0comments
He added that he hadn't "spoken to her in a while. I'm not gonna lie. I'm gonna be honest."
As for Ren's potential relationship status with Manheim? Fans will have to wait to find out.