To tell you the truth, I am not sure that Emily is that attached to Homer in particular. He represents the only "love interest" that has been an option for her, though. Her father discouraged all suitors as being not good enough, most likely motivated by a desire to keep Emily at home to care for him. Homer is the only gentleman caller Emily has, and while it appears that he might not have planned on staying with her, Emily certainly made sure he did!
Now what I have always wondered is whether or not Emily had her plans in place from the beginning. You will notice that Homer is not from the South, and he is someone who would probably not be missed by the townspeople. If Homer disappeared, people would just assume that he left, which is exactly what they did assume. Was Homer deliberately chosen so Emily could keep him around forever, or did this idea come to her later? Can you find any evidence in the story either way?
In the short story "A Rose for Emily," Faulkner depicts Miss Emily as eschewing most company and society. Growing up with a father who would not let her socialise normally would mean that she would have been socially awkward and inept anyway, and probably wouldn't have been very popular. When this happens, a vicious circle often happens where the less person socializes, the less sociable they then want to be. It could be that Emily attached herself to Homer because it was easy and convenient for her in her own mind. She could then lavish all her "social affection" on a subject that wasn't real, and use him as an excuse to socialize no further, or hang out with the townsfolk or make any effort at all.
She buys arsenic for him, even before they are married. She buys him a suit--the only one he will ever need. And she buys him a gold-plated toilet seat. If you put the seat up, it looks like a gravestone.
This is the attachment of a necrophiliac. She loves death things: the south, her father, the Chevalier culture, Homer. A dead Yankee is better than a live one.
She hates the guy while he's alive. They're as mismatched as you can get: she's a belle debutante, and he's a construction worker. She's daddy's little girl, and he's gay (Faulkner explicitly says, "he likes men"). She's a Southerner, and he's a damn Yankee. All in all, her sleeping with him is the worst kind of incest for the South, much like Oedipus' sleeping with his mother was for the ancient Greeks.
According to The Faulkner Journal, the symbols that are shown in Faulkner's story are interconnected in a way, and a lot is left for the reader's own establishment of a connection, depending on what Emily represents to you specifically.
In this case, however, we know for a fact one thing:
Emily might in fact be mad (or have a serious condition that is exemplified by her denial of the death of her father, the stubborness in changing her ways, her keeping a modern day slave in the house, and her extreme reclusiveness.)
Many studies in Faulkner declared Emily a person with extreme social anxiety and often people of this kind tend to attach themselves to one person only, if anyone, and in this case she opted for Homer Barron.
She, therefore, was attached to him for many reasons:
1) He filled the male presence that provided her a form of safety after her father died.
2) He represented the gentlemen callers that her father never let her receive (even in times when that was the custom), although Homer would have never been good enough either.
3) Homer represented a window into a different world, albeit the North, and also we know about his tendencies, but- had Emily ever dared rebelling against anyone? Could this have been her "TEENAGE REBELLION" taking place years later as an unfinished business?
4)Emily tried as best as she could to lead a life that existed only in her memories, and her imagination. Whatever was outside that mold was not part of her reality. Hence, Homer not turning into the gentleman caller and future husband that Emily was SUPPOSED to have, may have made her, like she had done before, break away from that reality, get rid of him, and continue her fantasy in her head.
Hence, these might be some of the reasons why her co-dependency reached such high levels.
In the short story "A Rose for Emily" Miss Emily lived with a powerful and well respected father. He was probably very choosy as to the type of men she could take. She lived in a small town where everyone knew everyone else. Her chances for meeting someone new were very slim.
After Emily's father’s death she was left alone. She had no other family in the area. In some ways this created a freedom for her. When she met Homer and started having him, despite him telling people in bars that he preferred men, she finally found someone.
Emily was probably sure that her chance for love and romance would not come again and so she latched onto Homer to the point of killing him when he tried to leave her.