The speaker is guarding a painful secret, and a lover is trying to coax it out. At first the silence feels like a defence: the speaker compares it to a garden full of dead and dying flowers, something private and ruined that they would rather not show anyone. The kiss at the start becomes a kind of questioning that gets no answer.
Then the poem shifts. The lover doesn't pry; instead they open the speaker up gently, and the line "bones need not be broken / to be open" captures the surprise of being vulnerable without being hurt. The lover's blue eyes become an ocean that lifts the "poison" away like vapour and brings the speaker back to life.
The ending is a nervous invitation. "Let me in" and "sink or swim" admit that trust is a risk. The mood moves from guarded and heavy to tender and hopeful, with fear still lingering underneath.