SUBREDDIT: r/relationships
TITLE: Me [24M] with girl [28/F] I just met - what's the etiquette for leaving her place?
POST: So theres this girl I met yesterday at a  beach party. We spent the whole day together, then went back to mine. She didn't want to have sex as we just met but we fooled around a little at mine, before she walked home. I'm seeing her tomorrow for (in her words) a "quick dinner". 

Now I'm thinking quick dinner might involve dinner then back to hers/mine which I'm fine with. But if I go back to hers, as someone who has always brought girls back to his apartment and never gone to a girls place, I have no idea what the etiquette is. Do we just have sex then I get up and leave? Do we have a cuddle before I leave? And if so, for how long? Do I wait for her to fall asleep before leaving? I wouldn't normally care if it was a one night thing, but I'm thinking of pursuing a little more with this girl so don't want to come off as needy by overstaying my welcome, but also not coming off as a douche bag by just fucking and leaving.
TL;DR: 
What is todays etiquette for a guy who doesn't want to come off as needy or as a douchebag when you go to her apartment?