I wouldn't live my life by that rule.
BUT, if Dante really likes her, and she doesn't want a relationship, then I would absolutely dump her and tell her it's because you want more, you're not happy with it being so casual.
Either she agrees and they're serious, or she tells him fair enough and they stay split up. Which is by far the better option. The last thing Dante wants is to be hanging onto this girl with it being casual whilst he gets more and more into her because of the whole wanting what you can't have phenomenon, because when she gets bored he'll be heart broken.
If she doesn't want anything, best to end it now.
If she does, then breaking it off with the reason being that he wants more will be what causes her to realise it.
As much as I'd like to suggest to keep nailing her, if Dante is into this girl then he needs to act
I don't want to sound brutal, but this is bullshit. All this will show her is that she can keep it casual and still get treated like a queen. By all means give her some special treatment. BUt if you act like a lapdog she'll treat you like a lapdog. She needs to understand that yeah you're a nice guy, but she doesn't get it for free.
It's easier said than done, I know from experience, but you have to break it off. It's the only way it'll work, if that makes any sense. Otherwise you're heading for the friendzone, and that's a horrible place to be.
Y'all need to bookmark this and refer to it if ever in this situation in the future.