After our metal bondage exercise series on the treadmill, we thought we’d invent something new for the girls to have a workout. Chaining them to an exercise bike would be fun! Not releasing them until they burn a set number of calories. So we invited our friend Natalia Forrest to try this. Just before she arrived, we thought it would be even better to replace the seat with a steel dildo! Natalia was not so sure about this. and she…