Can I have guests mix their own liquor drinks at our wedding?

We are having a very informal wedding. It is a rustic wedding at a friends house and I know most of our friends who are heavy drinkers will show up with ice chests full of their own alcoholic drinks. I do want to supply some alcoholic beverages such as a keg or two, and several different types of liquor with mixers and champagne for the toast. I want to do this mostly for those guests who will only have 2 or 3 drinks throughout the night. I plan on setting up a table where guests can mix their own drinks. Is that okay? I just don't know anyone who could bartend?