you'll need to guage it on an individual basis. There will be some girls looking for a fuck buddy (dont call it that to the girl) and some girls lookin for a proper relationship.

Whatever you are after make sure you tell the girl before she gets the wrong idea. Not many girls will be expecting a full on relationship after a night out and a day 2 together so dont feel you have to make it obvious what you're after straight away.

After you felt you've spent enough time with her to tell her what you're after then tell her. If you're after a fuck buddy, tell her you're only looking for a bit of fun and that you hope shes after the same. If she says no then apologise and tell her that a relationship is not what you want.

If you want a relationship (only ask this after spending quite a lot of time together, you'll know when its happening anyway) then just say you really enjoy spending time with her and you want to take it a step further or want to make it official or whatever.

Do not lie to a girl(s) and say you want to keep seeing her and see other girls behind her back. Let her know you plan to see other people.

Sleep with her first. Second or third time you see her after that, have a very short, simple conversation where you explain that you are OPEN to commitment but at the moment it's not what you're looking for. What's important is that when you're together you have a great time, and to enjoy that now while it's happening. If it leads to more then great, but otherwise it's not exclusive for now and she should understand that.

Preferably, say this while you're having fun at that time, and say it like "so if this isn't what you want then you should step away now because otherwise feelings could get hurt."

The two factors at work here are (1) people generally go with the inertia of a situation. If they're having fun they want to continue doing it. If she's having fun and you say she has to choose to back away, she's more likely to say it's ok and stay (2) By framing it as "I don't want this to be exclusive NOW, but am open to commitment," if she wants you to commit then she's gonna have to prove it to you by doing things to please you i.e. you build her compliance into the entire subtext of the relationship as it progresses.

Be up front. Most women are open to a friends-with-benefits scenario, but they need to know what they're going into. Nothing is worse than meeting a great guy and slowly realizing he doesn't want to go further.

And don't spend too much non-sexual time together. No cuddling, no watching movies, no lunch dates. That shit fucks with your head as a woman - "he likes hanging out with me, loves fucking me, and yet he doesn't want to be with me, wtf?!"