shy when it comes to talking dirty???

Is it just me or are there more ladies that do the same?? When I'm in the mood to have sex with my husband I have all these dirty thought but I can never get the nerve to say it aloud or to act on these thoughts. It's like I get really shy. Why do I do this? I need to find the courage to say out loud and act on these things I think of trying but I am nervous about what he may think since we have been together for 8 years and I have never done it. I just want to make sure we keep it interesting. Can anyone help??