Confused about asexuality?

I know someone who would be considered asexual, but it makes no sense. He says he doesn't have sexual attraction ( I had to explain it to him as a feel-good, curious, intrigued feeling), and that he believes men and women are the same. Boobs= pectorals to him and sex is boring. He's only had one crush, and it's his girlfriend that he's with. But some things arise that don't make sense? He says homosexuality is weird to him, people and things can be "sexy" ( he can't explain what that means), and he assumed he was heterosexual, because he didn't know there was asexuality. I asked how he could assume, and he said he didn't know he just did, but he's never understood what the point of men freaking out over boobs and women was. What confuses me is that he said he stopped caring a while ago and that he thought about sex, but not in a while. So is it hormonal? Or asexuality. I'm a close friend, and his gf also wants to know.