All I can say is Facebook is from the devil! I had an account and got rid of it. I was shocked two weeks into my using it how many ex-boyfriends and guys who were interested in dating in the past, but got no where came sniffing around looking for a "hook-up" under the guise of
"just being friends".
Let's put it this way, my DH was starting to get really annoyed. I got rid of my separate account, and we now share one. I was sickened by the fact that many of them had wives who knew nothing about their accounts.
The other thing I learned is all of the "sniffers" had only female friends and a few male friends, but never their wives. All of the "faithful" guys had their wives included on their accounts as a friend...and regular interaction with them on the "wall" etc.
The really sleazy "sniffers" even went as far as to create an account using a different name/handle.
I'd ask your husband if you can join his friend list. If he flat out says no, you've got something to worry about. If that happens, I'd even consider doing a little investigative work of your own and create an account with a different name and then ask him to join to see what he does. Say you've seen him at work and want to get to know him...or something.
I've concluded if you're married and have a career, you have no business putting anything but family pics and updates and messages out to the family on Facebook. Anything else is a recipe for trouble. Good Luck.