<human>: Can you succinctly summarize the text in 1-3 sentences?

Alright, I know this probably seems incredibly lame cause I'm 22 and I can't even figure this out for myself... but, I've been dating this girl since late October and made the relationship official a couple months ago. 

She lives around an hour away from me as we go to different schools and when we visit we'll typically hang out all day every other weekend or so. I have never had a girl stay the night before but I really want her to. I've kind of hinted at her staying the night a few times before but she always has to drive all the way back home that night to be ready for whatever she has to do the next day at school. Whenever I'm visiting her, there always comes a point in the night where she sort of off-hand mentions something like "Looks like it's going to rain later... you'll have to be extra careful when driving home tonight!" So I pretty much know what her intentions are at that point. And then I'll end up leaving at like 1 or 2 in the morning to drive an hour home. This happens pretty much every time I visit her at this point so I feel like the "just let it happen" advice won't work anytime soon. 

Sometimes when I'm visiting her, I really want to stay at her place, if only to at least avoid having to drive home so late at night. I never tell her this though cause I don't want to "invite myself over", cause I fear that might be rude. Maybe I should have been more upfront about this with her?

I'm having her come over this weekend and I really want to have her stay the night. Do I mention this to her beforehand or while we're hanging out? Also there's kind of an assumption of sex that comes along with this right? I've never had sex so I have no idea how to handle that either. So... if you have any advice regarding that too, then that'd be fantastic.
<bot>: Want to have my GF of a couple months stay over, not sure how to bring it up with her and I don't feel that it will happen organically at this point.