The 25-year-old singer confirmed she's "friends" with Jonas on Wednesday's episode of The Ellen DeGeneres Show following reports her song "Ruin the Friendship" is about her feelings for the recording artist.
"Something that I will always keep to myself is who I write my songs about," she told host Ellen DeGeneres.
Lovato agreed with DeGeneres that she and Jonas are "friends" who "play songs" for each other, but sidestepped further questioning by telling the television personality the song is about her.
"Ellen, I want to ruin the friendship with you," she joked before explaining, "It means I'm secretly in love with you."
Fans speculated on social media last week after Lovato appeared to sing about Jonas in the songs "Ruin the Friendship" and "Only Forever" from her new album, Tell Me You Love Me. Lovato recently told Vice the songs are about the same person, but didn't mention her crush by name.
"I was frustrated with a certain situation," the star said. "And I was like, 'You know what, I'm just going to write about it.' And so I did, and sent [the songs] to that person, and that was interesting."
"They knew [about my feelings], but neither of us had acknowledged [them] before," she shared. "And then it turned out that person had written a song about me, and we exchanged songs."
Lovato and Jonas co-starred in the Disney Channel movies Camp Rock (2008) and Camp Rock 2: The Final Jam (2010). The pair have since collaborated on music, including the song "Avalanche," and toured together.