Njogu_Magz builds the poem on two parallel portraits: a woman as a stagnant pond and a man as a bonfire. Both are described by what they lack. She is muddy, mossy and choked with hyacinth, so nothing lives in her. He burns everything that comes near, so nothing is safe with him. The imagery suggests that each has been shaped by pain, her "tears and tears of pain," his rough, hard fuel being "slowly added."
The third and fourth stanzas turn to other people, who use them and move on. They swim in her, leave their dirt and spit in her; they warm themselves by him and leave him in ashes. The repeated "Spat in" feels bitter, as if the speaker knows this treatment well.
Then the tone shifts. When the two meet, they make "burning water," something spectacular. The mood moves from bleak and resentful to quietly hopeful, though the last line, "dangerous yet calm," keeps a note of caution. Their pain hasn't vanished; it has become a strength.