"It was written during and after a break-up," she coos down the phone from Sweden. "The whole EP is about one relationship. Habits is just one part of the story, the after part."
It helped her get over the guy, but it also helped the pair resurrect their friendship, Lo says.
"He thinks it's really cool. I wasn't sure but I talked to him the other day and he's kind of amazed that our story became a whole album. We are [friends] now but it took a while."
Habits will undoubtedly be one of the highlights of Lo's New Zealand shows when she opens for Katy Perry over two nights at Auckland's Vector Arena.
Kiwi fans will be lucky to see her play. Lo sent a tweet from her Auckland hotel room saying doctors had found cysts on her vocal cords that required "urgent" surgery.
She told worried fans she was cancelling all shows for the next two months. But promoters say Lo is okay to perform on Friday and Saturday night before she heads back to Sweden for surgery.
In her interview with the Herald before those tweets were sent, Lo said she was looking forward to performing in front of some of the biggest crowds of her career.
"We've mostly done club gigs and smaller venues, so I'm really excited about performing on a big stage. I don't have choreography, but I do move a lot and get a bit spastic on stage. It's going to be overwhelming."
Her ultra-personal and occasionally explicit music, showcased on recent singles Not on Drugs and Talking Body from her September album Queen of the Clouds, helps Lo connect with fans.
"I get a lot of letters and emails from people saying they can relate and it's great to have someone saying they're feeling what you're feeling," she says.
But reliving the pain she pours into her songs on stage every night isn't the easiest thing for her to do.
"You have so much adrenaline and people are singing along to your songs - that's a big happy emotion. But what you're singing about you get really emotional in another way.
"I'm still connected to the songs, but you connect to the audience and feed off their energy and it becomes more of a happy moment."
Music profile
Who: Tove Lo.
Where: Opening for Katy Perry, tonight and Saturday night, Vector Arena.
Also: Album Queen of the Clouds, out now.
