When your partner suggested you try some bondage to spice things up, you never imaged it would start with 3 weeks of chastity followed by a shibari session ending in free use for all your partner's friends.
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.
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.