Songfacts®:

• This emotional ballad, credited in part to hitmaker Max Martin, is about a breakup. It finds Nick Jonas singing about how he can't stop thinking about his ex. In the middle of making Last Year Was Complicated, the singer split from his longtime girlfriend Olivia Culpo. He said the parting provided a lot of inspiration for this song.
  
  Nick Jonas from Reddit: "Last year was complicated, because no matter who you are or what you go through in your life, we all deal with the same human issues. I started writing the record and then had a breakup that became kind of the main thing that the songwriting was about."
• The song's lusty video finds Jonas and Pretty Little Liars actress Shay Mitchell playing a troubled couple.
• Bebe Rexha originally wrote this song for Rihanna in the early 2010s. She explained to OfficialCharts.com how it ended up being recorded five years later by Nick Jonas.
  
  "I remember pitching this song called Under You for Rihanna, but they decided it was too low in the key, so I passed it on to Usher to cut it," she said. "A year later Usher hadn't cut the track because he'd decided he didn't want to put new music out, so I sent it to Nick Jonas, who ended up putting it out on his album."