The speaker is caught in a strong, nagging desire, and the poem never says what it is. We only learn the shape of it: something they have promised not to do, something that makes other people hate them, yet also something nobody notices or expects from them. Those last two details pull against each other, and that tension is where the poem gets its ache. The act seems both condemned and invisible, as if the speaker is judged harshly while still going unseen.
Because the "it" stays hidden, readers are pushed to fill the gap themselves, and the poem works whether it's a small temptation or something much darker. The short, repetitive lines build pressure, and the final break, "I want to do it... / So badly," feels like a held breath giving way. The mood is tense and confessional, a private struggle between restraint and longing, with the speaker teetering right at the edge of giving in.