Should I Tell Him That I Care?

I have this very very tight knit group of best friends, two boys and two girls, including me. One of the friends and I had a discussion about trying to keep each other very close because most of us fear that we may slowly drift from one another. So she said that in order for us to prevent that from happening, I should marry one of the guys.

Well actually, one of the guy friends and her both agreed. To an extent I believe that they were just half-joking. My problem is I really like my guy friend and have for quite a while. My girl friend knows him longer than I have and she said that he was kind of serious because of the fear of being alone for the rest of his life. As I said before, she knew him longer than I and there was a time that I believed that my guy friend liked her (he still does) and they were going to date each other, but she is in a relationship (so sorry that this is long). She actually wants me to go out with him.

My question is should I tell him how I feel? Again I do apologize for this long story. Thanks