Search Results: casual or serious dating

I've always found this a rather perplexing issue.

One type of girl will only date people after she's interacted in a casual group setting long enough to become good friends. She will usually get uncomfortable when a guy she's just met shows romantic intentions. She believes a guy who is worth her time can wait patiently while she decides how she feels about him through the course of friendship.

Another sort feels the opposite. She gets turned off by men who like her, but guard their intentions under the casual guise of friendship. She might say that any man worth her time will show how serious, dedicated, and interested he is from the get-go. She can become frustrated by a man who is subtle or cautious in showing romantic interests instead of "manning up" and showcasing his intentions as soon as he is aware of them.

Which of these categories do GAGers prefer to live under?

Also, how is a man to handle the first impression with a woman when he doesn't know which philosophy governs her expectations?

This girl and I have known each other for 4 years, but we've only been together for 9 months. We're both 19 and we are each other's first love, sex, oral, a lot of things. We were very close before we actually started dating so we know pretty much everything about each other. I love her more than anything in the world and I couldn't even imagine finding someone better. She has her own place but she pretty much lives at my apartment.

Earlier this week, she ended it with me, saying that everything is too serious and that she is young and just wants to have fun right now. A couple of days Later we talked and she said that she wants to experience what it's like to be with other guys. But she said that she wants me to wait for her. Until we finish college, which is in about 2 and a half years. She said that I can have sex with other girls, just no relationships and she will do the same (but with guys).

I really don't know what to do. I love her so much and I want her to be happy. I don't really have any interest in casual sex, I just want to be with her. I don't know what it is about her but she just makes me feel happy. I literally cannot describe the depth of my love for her, and I would do anything for her, but I mean, what happens if she meets someone else? I understand that she wants to experience what it's like to be with other guys. Honestly, I think I could accept that. But I don't want to wait around waiting for something that may never happen. Should I wait for her?
I know that you guys can't really answer this question for me, but advice would be good.