Music and Lyrics

As one of the founding members of the band PoP!, former pop star Alex Fletcher (Hugh Grant) enjoyed considerable fame and success during the 1980s and early 1990s. Fifteen years after PoP! disbanded, Fletcher is a self-acknowledged has-been, reprising his 1980s hits for audiences of his now middle-aged fans. After years of performing in increasingly humiliating venues (such as high school reunions and theme parks), a chance to recapture some of his former stardom arrives when mainstream pop singer Cora Corman (Haley Bennet) asks him to write a duet for her to be called "Way Back Into Love". To Alex's dismay, however, he has only a few days to compose the song. Furthermore, he hasn't written anything in ten years, and even with PoP!, he usually only wrote the melodies, not the lyrics. His manager (Brad Garrett) helps him to search for a lyricist, without much luck.Alex meets former creative writing student reeling from a disastrous romance Sophie Fisher (Drew Barrymore) when she comes to his house to water his plants. Sophie is also a writer with little confidence in her abilities. While Alex and a hired lyricist try to come up with lyrics, Sophie comes up with words to herself while watering the plants. Alex requests Sophie's assistance on the song, and although she initially declines, after a series of conversations with him, she agrees to collaborate. There are signs of a budding romance as the two write the song, which they finish in three days. Meanwhile, Sophie runs into her ex-lover Sloan Cates, who wrote a very insulting book about her, and whom Alex assists Sophie in trying to confront, after which they go back to Alex's house and make love under the piano.All seems well when Cora likes the song and decides to perform it and put it on her next album. However, she adds a highly sexualized "steamy and sticky" Indian-themed vibe that clashes with the spirit of Alex and Sophie's work. Sophie is determined to talk Cora out of the addition, only to find Alex vetoing her efforts for fear he'll lose the chance to work with Cora and finally revive his career. In the ensuing argument, Alex reveals a deep pessimism regarding the music business, admitting that Cora's addition is awful but viewing it as the cost of doing business. Scandalized by Alex's willingness to demean his talent and hurt by his argument that she is refusing to live in the real world, Sophie leaves him.Cora invites Alex and Sophie to the premiere of her new tour, at which she and Alex are due to premiere "Way Back Into Love." However, to Sophie's surprise, Cora announces "a new song by Alex Fletcher", and Sophie begins to leave, under the impression that Alex stripped her of her songwriting credit. Instead Alex performs an entirely new song ("Don't Write Me Off") written by himself about his and Sophie's relationship, despite his admitted incapability of writing lyrics. Backstage, Alex tells Sophie that he convinced Cora to remove the risqué Indian-theme music of "Way Back Into Love" as an attempt to win her back. The original version of the song is performed by Alex and Cora, after which Alex and Sophie kiss backstage.

Question: Where does Alex and Sophie ended up kissing?
Answer: Backstage