The repeated structure of the two stanzas gives the piece a wonderful sense of completion. Simple words are chosen to highlight the basic, almost elemental, nature of what the narrator expected from their betrayer.
Misplaced trust is a constant theme in many writers' works, and there is good reason. It is a powerful emotion, to be betrayed where we expected trust and integrity is thunderous, but also an exceptionally common one, man is not the most admirable of creatures.
I enjoyed this short little piece, and I am enjoying reading your work. Please do keep sharing,
A.E.