Listen I love whore regulus as much as the next guy but something about demisexual Regulus only being able to have a sexual relationship after forming a emotional bond with someone makes me FEEL something.
If you mix in a little bit of him wanting to experience a sexual relationship but never being able to picture it without making himself uncomfortable. Him struggling to understand why he can get turned on but never feel like moving forward with someone. Him thinking for a long time he's asexual bc he just can't but at the same time wants to so it doesn't make sense. Snogging is fun and enjoyable but "please don't touch me like that and no I don't want to go somewhere quiet".