Maria's poem is a single run-on thought, the kind of message someone types and never sends. The speaker wanted to write "i miss you" to a former partner, or at least someone who once mattered a great deal, but stops short. The reason is blunt: "its not my place anymore." The speaker no longer has the right to say it, because the other person is "missing someone else now."
What gives the poem its sting is how plain it is. There's no punctuation, no capital letters, no dramatic imagery. It reads like a text message, which makes the restraint feel real and a little raw. The speaker isn't angry, just resigned, and the final line quietly admits they've been replaced.
The mood is sad but controlled. Nothing is shouted. The pain sits in the unsent words, and in the speaker's decision to swallow them rather than risk being unwelcome.