Seymour assures Audrey, "Suddenly, Seymour/Is here to provide you/Sweet understanding/Seymour's your friend." Then at the end of the song, Audrey proclaims, "Seymour's my man!" At least in the movie, Seymour and Audrey perform a Big Damn Kiss after this.
Throughout the film, Seymour is convinced that Audrey would never go with a guy like him; especially without money. Cue Audrey admitting to him near the end that she fell for him ever since she started working at the shop.
"And if I'm in the plant, then I'm part of the plant, so, in a way, we'll always be together..." That entire scene is both a Heartwarming Moment and a Tear Jerker.