My husband does it all the time. If there's a vegetable side, you better believe that's staying in the kitchen. There's almost always fries available if there is a kids menu offered (don't forget about the kinds menu - if they have it for them, they can put it on your plate as well). My husband has also just asked what else is available and chosen from those selections.
I don't think my husband ever eats anything exactly how it is presented on the menu. There's a substitution or deletion somewhere on there.