As far as the rating changing - I'm going to flat out say now, it's not because I'm considering putting in a sex scene. There won't be one. So if you're one of those "NC17 or nothing!" people, here's your warning to not bother.
Loveless: Soubi/Ritsuka: PG13 (May raise later. I don't know.)
He likes how Soubi takes care of him. He likes doing the same thing in return. He likes it here, in the apartment, and wonders what it would be like to live here.