Songfacts®:

• This song deals with a breakup that is crushing for the singer - one of those relationships that ends with one person devastated and the other moving on in good order. The line, "You have no right to speak to me so kind" implies that the person who broke up with him still wants to be friends, but the heartache is too much to bear, and he needs her out of his life so he can move on.
• Phil Collins was in a period where he was writing extraordinarily gut-wrenching songs like "Against All Odds (Take A Look At Me Now)," but he didn't write this one. "Separate Lives" was composed by Stephen Bishop, who had hits with "On and On" and "Save It For A Rainy Day." Bishop had a small part in the movie Animal House, where John Belushi smashes his guitar. On the set, he met Karen Allen, who is known for her roles in the first and fourth Indiana Jones movies. Bishop told us that he wrote the song after their breakup, adding, "I actually called her from the room in my hotel... poetic license don'tcha know."
  
  Regarding his songwriting process, Bishop says: "In Nashville they make songwriting a real job, they get to it. I tend to get a bit lazy on my songwriting, especially if I'm happy and content. I write much better when I'm heartbroken and sad or melancholy." (Thanks to Stephen for the info. Check out his website at stephenbishop.com.)
• This was featured in the 1985 movie White Nights, starring Mikhail Baryshnikov and Gregory Hines. Stephen Bishop sent the song to Phil Collins, who loved it and recorded it for the film. Bishop changed some of the lyrics for the movie version.
• This received an Oscar nomination for Best Original Song, but lost to Lionel Richie's "Say You, Say Me," which was also from White Nights. The film was directed by Taylor Hackford, who had a knack for turning out #1 hits from his movies. He also had chart-toppers with his movies An Officer And A Gentleman, Against All Odds and La Bamba.
• Marilyn Martin was a prominent session singer who landed a record deal with Atlantic after singing backup for Stevie Nicks on her 1985 album Rock A Little. An executive at Atlantic thought she would be a good fit for this duet, and pair her with Collins, who approved. Martin had a minor hit in 1986 with "Night Moves" before she moved on to a career in real estate in the '00s. She later recorded Christian music, and in 2017 joined Sharon Celani as a backing singer on Nicks' 2017 tour. The next year, she and Celani toured as Fleetwood Mac's backing singers.
• Stephen Bishop recorded his own version of this song on an album called Sleeping With Girls, which got a very limited release. "The way I perform the song is a lot different from the Phil Collins version," Bishop told Songfacts. "He liked my version as well, so these days he does it more like me in concert. I mean, when you say 'you have no right,' that gets under your skin. He just kind of glossed over it in his original version.
  
  It's an important song for him. It's an emotional song. I've seen him do it in concert and people just love it. It gets their attention."
• Here's a fun fact: When Martin toured as a backup singer with Fleetwood Mac in 2018, she was the only musician on stage with a #1 hit to her name outside of the group. This in a lineup that included Stevie Nicks, Neil Finn of Crowded House, and Mike Campbell from Tom Petty & the Heartbreakers.