College so far (update)

So ever since my last post about college, many things have changed for the better. My college offers a "Freshman Seminar" type class, and it has around 30 students that are in my major (Biology). This class and my Biology class came in a package, and I took it so I could have Biology as a freshman. And in this class, I have been able to become friends with 2 people that takes college as seriously as I do. The three of us notice how the rest of the freshman class plays/parties around and hold studying to the last minute. The Freshman Seminar class holds a study group that meets every two days, that are only ran by the freshman students. We noticed how disorganized things are in those study group sessions, which made us to make our own study group of three. So far, it has been really successful. The three of us are very compatible with each other, share many things in common, and we each have our own motivation that drives us to be better in school. The only bad thing is that other students are realizing how crappy the study group sessions given are not working. They've notice how the three of us have been together in the library A LOT more recently. We've agreed to each other to not let anyone else join our study group because we feel that a group more than three will be too much to handle. Whenever we are asked if they can join us, we find it hard to decline their offer(some of the students are really nice people, it's just... we feel that they are just "outsiders"). But, I know that one day (and that day is getting closer and closer), that one of us is going to have to be blunt and tell them "No". I'm not scared to say "No", it's just that I don't want to be seen as an asshole by not allowing them to study with us. I guess I'm just selfish when it comes to knowledge and education.

Short:
In a study group of three that works really well, the rest of the class wants to join us, and we have difficulties saying "No" to them. But not for long...