It's been 25 days of being locked up, at the start you swore you'd never suck dick, but a strap on doesn't count, right? Now that its the only way to earn release, you hope it still works.
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.