Having been friends with someone a long time can make you begin storing somewhere in your brain that they would be your go to if something social comes up. Since this dance is apparently new for you, you maybe hadn’t thought about someone asking you, or how that would make you feel. You haven’t been asked by two boys. You have been asked by only one boy. Your friend might have no interest in going, and if you start throwing hints, it could make him feel obligated, in which case you would both be miserable. Also, he might have someone he is thinking about asking. Dating should be fun, not obligatory. It sounds like a nice boy has planned a nice date. There is no reason for you to feel like wanting to go is a greedy thing. It might be just the one dance, and never anything more, but that is okay.