My mom's pretty cool about stuff like that. When she gave me the "sex talk", she said- "Sex is wierd at first, but once you get the hang of it, its a lot of fun!"
We don't ever get into details, but she knows what goes on.
My dad, on the other hand... I told him I was on birth control (I have a hard time hiding things from my parents), and he looked at me and said, "I'm going to go throw up now." hehe. Its just hard when daddy's think their little girls have sex.