He was writing this crazy, puppet musical [Avenue Q] and so the word, fixer-upper, has always been in my lexicon.Robert Lopez further elaborated on the song's context within the musical:[3] When we realized that Kristoff was going to have this relationship with the trolls which was kind of the key discovery we realized that it was kind of like okay, he’s bringing this girl that he’s not dating home to this big, ruckus family and they’re gonna misinterpret the situation.
So we thought oh, gee it’s gotta have that kind of New York dating song cabaret feel and so that’s how the music kind of came about.The song is sung when Kristoff brings Anna to his "family" - the trolls who treated Anna after Elsa's earlier accident.
The song starts with the trolls asking Anna what is turning her off from dating Kristoff, like "his unmanly blondness" or his tendency to "tinkle in the woods".
They manage to get partway through the vows before Anna collapses and falls into Kristoff's arms due to her frozen heart.
IndieWire described the song as an "arbitrary upbeat ode to love's ability to triumph over imperfection so incongruous it's displaced to the middle of Frozen's soundtrack CD".