I took a fellow glider rated airline pilot for an aerobatic ride in an Extra 300L one day. On the way back to the airport I asked him to take the controls so I could tune the radio and get ATIS, we did the full positive exchange of controls routine. As we descended past the cloud bases the usual turbulence began. That's when Joe began a series of poor quality aileron rolls.. "What are you doing to me I'm heads down back here? Keep it level!" I exclaimed.
"I thought you were doing that!" He responded.
The Extra has neutral roll stability and when we flew through the turbulence the airplane began to roll as a reaction to the displacement and just kept going! My buddy thought I was having fun messing with him I guess. In hind sight I should have explained the consequences of the lack of stability in the airplane.