Here the speaker is cleaning up after a relationship that has ended. Someone's name, written in red letters, has been stuck on a white wall, and the speaker peels it off piece by piece. The scraps fall onto the floor, and the next job is to scoop them up and throw them out the back door. It's a small, physical chore, but it stands in for letting a person go.
The speaker sounds cold and a little satisfied. They say they "enjoyed" the peeling, they gave everything while the other person gave almost nothing, and they claim they "really just don't care." That last line may be protesting a bit too much, since someone who truly didn't care probably wouldn't describe the cleanup in such detail. The final lines turn into a blunt lesson: you get what you give, and that's fair. The mood is bitter, controlled, and quietly final, like a door being shut without slamming it.