Avril Lavigne felt an "immediate connection" with Mod Sun.
The 'I'm With You' hitmaker was romantically linked with the 34-year-old singer in February but before then they had worked together on duet 'Flames', and the 36-year-old pop star revealed the pair hit it off as soon as they got into the studio.
Avril told People magazine: "[We] had an immediate connection from the first day in the studio.
"He's an incredible artist and producer. This is the first of many. Proud of what we made with 'Flames.'"
Last week, the pair released a stripped-down, acoustic version of the duet and Avril thinks they have brought extra "emotion" to the "very special" song.
She said: "'Flames' is a very special song. "I love how the acoustic version turned out. It really brings another layer of emotion to the song."
Her partner explained he wanted to "offer a bright side to the story" with the new take on the track.
He added: "I felt like sonically I could paint that landscape through acoustic guitar and a string section.
"I wanted to make something that felt like we were performing in your living room."
It was previously claimed the 'Complicated' singer - who was previously married to Deryck Whibley and Chad Kroeger - was recently reported to have fallen for Mod after working with him in the recording studio.
A source explained: "Working together has brought them closer and Avril has a history of falling for people that she works with. She falls in love with them for their musical creativity and expression.
"Her working relationships often turn romantic."
Avril and Mod - who previously dated Disney star Bella Thorne - relished spending time together in the studio amid the coronavirus crisis.
The insider shared: "Avril and Mod Sun have been spending a ton of time together and getting to know each other better."
Avril previously insisted she hadn't given up on love, despite going through two divorces.
The 'What the Hell' hitmaker - who split from her previous boyfriend, Phillip Sarofim, in January 2019 - claimed she hasn't allowed heartache to undermine her faith in true love.
Asked if she'd like to get married again, Avril replied: "I don’t really care so much about that; I just care about being in a healthy relationship and just being happy."
Tagged in Avril Lavigne Deryck Whibley