Lauren Jauregui channelled a heated moment in her relationship into her debut solo single.

The former Fifth Harmony star drew on an emotional moment with her boyfriend Ty Dolla $ign for the new track Expectations, explaining the lyrics and tone of the feisty song came to her one night her man was running late.

"Sometimes, when you're a little bit of a crazy b**ch and you've been working for a lot of hours, you just want to cuddle with your boyfriend - and they have to do work," Jauregui tells Billboard. "He had an appearance he had to do at the club, and I didn't want to go to the club because I'm a grandma (not a club type). He said he was going to come home, so I waited up, expecting him to come home, and then I didn't get any answers for a while about where he was."

The singer tells the publication the rapper ended up hitting the studio with fellow musician Future that night and was unreachable, so Jauregui got angry and admits she's "still a little Latina mad about it".

"I purged the emotion in it," she reveals. "I got all of the feelings out in the song, and then I called him right after and I was like, 'Hey, I'm not mad anymore'. I realised it was total bulls**t, my bad... If I can get my emotions out in songs, instead of acting crazy, that's fantastic."

Despite the misunderstanding, Jauregui credits her boyfriend for helping her develop her sound.

"Ty is also super supportive," she shares. "Watching him work also is incredibly inspiring to me, (especially) seeing the way he makes tracks come to life with his musical brain. I'm more of a lyricist. When I listen to a song, the first thing that I listen to is the lyrics. When he listens to the song, the first thing he listens to is the beat. We taught each other stuff about how to get better at what we do."