Idk what's different..

In past relationships, I've always been a very frisky person, especially with my ex of 3 years. I wasn't scared to try new things and the sex was constant and exciting. my husband and I have good sex but it is not very often and not very exciting. its hard to explain because I'm not sure it's in a negative way. it's like we get nervous around each other, butterflies and stuff. but I also think it has to do with the fact that he doesn't have a lot of experience before me either. I'm not super bothered by this, it's not a deal breaker by any means but has anyone gone through this or have any advice on how to change things?