Gigi's poem is about a past relationship that never became a real partnership. The speaker remembers a boy who brought her both joy and tears, and who always said "you and i," never "us." At the time she brushed it off, but the small phrase turns out to hold the whole story: he was close to her, yet never fully committed to being part of a pair.
The speaker feels torn. She says he "had my heart clutched," as if he wouldn't release it, and then wishes he would "just let go." She wants to be free of him, but she also wants him to have stayed, and to have asked her to run away with him. That contradiction is the heart of the poem. Her longing and her resentment sit side by side.
The mood is wistful and quietly sad. The short, plain lines and repeated phrases feel like someone going over the same memory again and again, still looking for the moment it went wrong.