MaryAnn, as I understand it, the biographical understanding of the poem identifies "your close friend" as Maud Gonne's younger sister.

That indicates that like many works of art this one is an invention: based on experience but freely re-imagining it. Unlike Yeats poems like "Easter 1916" or "In Memory of Major Robert Gregory" this one does not include proper names.

In my own thinking about the poem, I'm aware that his erotic obsession with Gonne was the great central attachment of his life, different in intensity from that to his wife. But I'm also very aware that he invents a relationship for this poem: far more fictional, in my mind, than "your close friend" is "it all seemed happy." Insofar this is about him and Maude Gonne, I feel like saying, "It did?" Or "Hah." Or, "And when was that?"

In other words, the words of the poem make me feel like he's invented an early-September evening scene, a "we sat together" that feels settled, almost domestic. The time of day and the sitting together suggests a post-dinner drink. The relationship with the silent "you" feels not so much stormy and tormented and as as if "you" are about to marry someone else as relatively ok on the surface, but worn and weary under the surface.

So, to get back to your actual question, the fiction of the poem seems subtly but distinctly different from WBY's actual life, or --to be honest-- my received fiction of that life.

(Gonne did marry the other guy within a year or two after the writing of "Adam's Curse," didn't she? These discussions tend to reveal, amusingly, the severe limits to my scholarship; my friends and family know that I tend to get matters of fact wrong. Especially those regarding time and space.)