Speaker/Shire
The Speaker, Shire, is shown to be unhappy with her love life and begins to question whether love truly exists. She reflects on her own parent's romance and there is a sense of longing to have what they had in her own disappointing relationship. She states that she "(thinks) of lovers as trees, growing to and from one another" but that all she does is carry around "loss."
Unnamed lover
Shire seems to be referencing and comparing her parents relationship to an unnamed partner. It is implied that his "quick" statement of love is proof that she/he does not really love Shire. She/He is also shown to not care enough for the relationship to fight for it, and instead chooses to "leave."