You knew they were also locked when they asked to lock you up, but you had no idea they expected you to match the time they already had in their belt, and since she was Ace it wasn't difficult at all for her to last the 3 years she already had.
You never thought you would find a girlfriend, so when the first girl took an interest in you came along you agreed to do anything for her. Now you are seeing what she really meant by anything.
Signing up for a medical kink weekend was on your dream list. The chastity belt was a nice touch, but the full denial was starting to really get to you, you cant remember the last time you went longer than 12 hours without orgasming.