In a high-class restaurant, I will eat Pizza with knife and fork.
Ditto! When I go to a real Italian restaurant that is well very posh and high class I wouldn't dream of eating pizza with my hands-unless I was with an Italian friend who decided to eat with their fingers as it's tradition....
On the other side-I only use a folk in places like Pizza Hut when I eat things like Pasta salad-their potato salad is lovely jubbly too :)