Axel and Roxas couldn't tell you why they kept going back to each other. Their relationship was dangerous, and both of them were completely aware of that, but why stop at a scratch when your main goal is self-destruction?
Roxas liked to tell people he kept going back because of love, because he loved Axel more than he could put into words and the thought of his life without the redhead made him feel ill.
Axel told people it was like an addiction, a habit. He spent so long with Roxas that it was natural to need him and he would start itching when he didn't feel Roxas' lips pressed against his own.
Neither of them could tell you the difference between love and addiction, and neither of them looked much into their relationship. It is what it is, and they enjoyed every second of it.
Roxas once asked if Axel ever had dreams about him. Axel admitted he did, but he skipped over the parts in his dreams where his hands were wrapped around the blond's neck, yelling at him to shut the fuck up because his voice had become worse than nails on a chalkboard. Axel would never tell Roxas the dreams of his blond bleeding on the floor because Axel wouldn't stop hitting him, or the dreams both of them were staring into the mirror, their faces bruised and bloodied from the fight they just had. No, those dreams stayed at the very back of his mind, only coming to the front when the lights went out and he slipped away.
He didn't know what the dreams meant, but he suspected that they were forming ways to get his hatred from Roxas out without actually hurting him. Axel didn't dwell on the whys of his dreams or how they should make him feel. It is what it is, and he enjoyed every second of it.
Axel had asked Roxas what he did in front of the computer every night, staring so intensely at the screen. Roxas said he was writing, but he would never let Axel read any of the words. He didn't know how Axel would react to their sex life being put out for the world to read or the ratings he gave the sex after everything was done. He wouldn't let Axel read his comments about how the redhead could use his tongue more, or how he had a deranged beauty about him while he was on his knees with Roxas' cock in his mouth. Roxas would never tell Axel that he wrote about their sex life, and their relationship to hundreds of people, and he would answer questions in such detail that he had people messaging him telling him they came all over themselves with his latest answer or story.
All of Roxas' fantasies were here, and he suspected Axel would leave if he read some of them. He had a fantasy of beating Axel so badly that his body matched his hair, and the only sounds that could come out of his mouth were broken whimpers. Roxas thought of that one over and over again, but he would never tell Axel that.
He didn't dwell on why he found the image of Axel broken to be sexy. Perhaps it was the sadistic side of him, but the excuses and reasoning behind his thoughts didn't matter. It is what it is, and he enjoyed every second of it.
Both of them had asked the other why their sex was never kind, why it always ended in stinging backs and bruised hips. Neither one would admit it was something they dreamt about, something they thought about, so they played it off as being in the heat of the moment.
Neither of them really questioned their relationship. They knew it was dangerous, twisted, disturbing, but it is what it is, and they enjoyed every second of it, even if it had the potential to kill them in the end.