"Tenerife Sea," first played in demo form at Sheeran's sold out Madison Square Garden shows, is "trademark acoustic balladry." Sheeran wrote the song at the 2013 Grammy Awards, where he felt "a bit left out," as he was there with his parents and "everyone else was doing drugs." Sheeran described it by saying "it sounds like a Thomas Cook brochure," and was in fact inspired by one, as "the sea was so blue and [he] likened it to someones eyes." He "was writing the song and the Thomas Cook brochure was on the table, and [he thought] "Her eyes kinda look like that sea, what sea is that?,"" leading to the name and some of the lyrics.
In a Billboard track-by-track review, writer Jason Lipshutz stated: "On an album filled with romantic uncertainty, "Tenerlife Sea" induces chills with straightforward emotion, as Sheeran begins the waltz of the chorus by repeating, 'So in love, so in love.'"