I need a man's advice! Please Help?

So my boyfriend isn't the most endowed man in the world. Fully hard he is at most 5 inches. We are having sex and it could start to be a problem because I don't really feel anything. He's good at everything else he does to me but I want to be able to enjoy sex as much as he does. Is there any way that I can fix this or do something with out telling him that I think he is small? Any advice will be greatly appreciated