Suppose that instead of the 1986 film changing the ending, they just put a "happy" song over the credits to make people happy. I wrote this song myself, though it's supposed to go to the tune of Crystal, Ronnette, and Chiffon, a song that was also written to go in the credits of the 1986 film (though it was discarded.)
Seymour begins singing (in voice-over, since the song would go over the credits). "It kind of sucks here."
Then, Audrey. "Being dissolved."
"Somehow kept conscious," sings Seymour.
"Our plot's resolved!" sings Audrey
"But I got you!" Crystal, Ronnette, and Chiffon back up Seymour's line with an "Ooh ooh, ooh, ooh!"
Now, Seymour and Audrey sing together. "But I got you!"
"You thought I was nuts but it all came true!" sings Audrey.
"It's like magic how we somehow survived!" sings Seymour.
"Even though I'd rather be alive!" sings Audrey.
"But I got you!" they both sing.
"Together inside!" sings Audrey.
"Assimilated and acidified!" sings Seymour.
"Though this isn't how we thought things would be, it's a happy ending def'nit'ly!" they both sing.
"Now we live in this plant and it's just great," they both sing. "Tied together in this painful fate. Though our skin's mostly corroded away, at least I'm with you while I decay!" The song goes to an instrumental interlude.
"This is disgusting!" says Orin, in voiceover.
"Shut up, Orin," says Audrey.
"Cuz I got you!" Seymour and Audrey sing. "Cuz I got you! Couldn't even leave if we wanted to!"
"There's no plant I'd rather die for than this!" sings Audrey.
"Locked together in a sort of bliss!" sings Seymour.
"Yeah I got you!" they both sing. "Yeah, I got you! We're glad the world got eaten through and through! We're glad about the murder spree! It's a happy ending def'nit'ly!"
"I'm burning up here..." sings Seymour.
"Burning with love?" sings Audrey.
"No, I meant acid," sings Seymour. "But yeah, love works too, I guess."
"So I got you!" they both sing. "Though I guess you could say things went askew, though things could have gone more perfectly, it's a happy ending def'nit'ly, def'nit'ly!" They then sing the last verse a couple more times as the song fades out.