Armen was taken aback. Surely this lunatic general couldn't be serious. All of the cadets were beyond shocked. To get as close as they were to the titanesses was unusual, and yet they were expected to spend the night in their most intimate area for an entire night!
The three titanesses before them were grinning deviously. Armen, Eren and Mikasa had all heard rumours about the titanesses they kept here. It was said that they were captured just after Wall Maria was compromised, and were chained up here in the training grounds to assist in giving cadets a close up look at their enemy. As far as Eren was concerned, since the first attack, all three of them had gotten too close for comfort with Titanesses already.
"The first cadets to take part in this final challenge tonight will be..." The general looked around as though casually picking cattle for the slaughter. "Ackerman, Jaeger and Arlert." He announced, and already Armen couldn't believe his awful luck. Mikasa and Eren remained stony faced and sure. They knew what their goals were in life, and this was just another obstacle in their way.
The general caught Armen's wavering stare. He was terrified.
"Will that be a problem, Cadet Arlert?"
"No!" Armen squealed a little too loudly. "I'm willing to do anything it takes to become a scout."
The general leaned in closer to him and grinned.
"Good, that's what I like to hear."
"What if they try to..." Armen stuttered, not wishing to make himself more of a target to the general. "...kill us?"

The general gave out a hearty chuckle.
"Haha, don't you worry about that, Cadet. These giant bitches are all tied up with titanium chains. They can't move a single muscle in their body. However it also means we have to give them diaper changes every week, otherwise these diapers wouldn't even stay around their waists. The amount of shit they produce is unimaginable. 
"And we're expected to sleep in there?" Eren asked sceptically. Even from where they were stood they could see that the diapers were going to be cramped and uncomfortable. The titanesses were medium sized, as titanesses go, and only stood about twenty feet tall. 
"It will be nightfall soon, and there's no time like the present, Cadets." The general said as he collected them from the ranks and lead them over to the three titanic women. The general stood them in front of a titaness each. All of them had been changed that day, but the three cadets could already see the tell-tale yellow sag of their diapers between their thighs. The women weren't wearing any other scrap of clothing, and all three were young, blonde, and had a pair of beautiful, full breasts. However these breasts could have crushed a normal sized human without any effort. The thought gave Armen chills. 

"Cadets," The general announced as he lead the three of them towards the towering beauties. Armen was shivering, whilst Eren and Mikasa maintained their composure, despite the absolute terror that was running silently beneath their stony faces.
“It is now your sworn duty, as soon to be Scouts, to enter the diapers of these three titanesses, and stay in their the entire night. You have, at any time, the option to bail out and escape the diapers by shouting 'I give up'. However, in doing so, you will obliterate any opportunity you once had in pursuing your dreams of becoming a member of the scout regiment. Do you understand me?” 
“Yes sir!” They called obediently, carrying out their trademark salute. The general lead them over to each of their titanesses.
“Right, Cadets.” The general said, as Armen stood in terror before the giant woman who looked hungrily over him with wide blue eyes and a shark-like grin. She looked to him like she could have only been 19 or so, judging by her face. Along her collarbone was the tattoo 'Cordia'. 
“These girls aren't going anywhere, Armen, so you don't have to worry.” The general said, not so reassuringly. “These chains are practically unbreakable. And these girls are only thirty-footers. They won't be anything to worry about. You just worry about that diaper.”  

Armen didn't need telling twice. All he could think about was that diaper. The way it hung between her legs like that, like it was mocking him. That was to be his prison for an entire night! How was he going to make it? He had no idea. But of course, there was only one way to find out. 
To his left and right, Eren and Mikasa approached their titanesses, neither one of them looking anywhere near as scared as Armen felt. They were both so much braver than him, with so much more fire in them. He felt so inadequate. 
“Cadet Arlert!” The general shouted, snapping Armen out of his thoughts. “Get a move on or you fail!” 

Armen hadn't realised. Eren and Mikasa were already ascending their titanesses, using the legs as supports and then swinging themselves over into the diapers. Both of them disappeared into the diapers without so much as a look in Armen's direction. 
“Please don't eat me.” He whimpered as he approached Cordia. She strained against her chains to get to him, no doubt to devour him, but she didn't have the strength to break free. Armen tentatively placed a foot on her giant toe, and started to scramble his way up her body. Her skin was soft and pale, and felt good under Armen's touch. He found her quite attractive, but in the same breath, terrifying beyond belief.
“I'm just gonna get in your diaper...” He mumbled in panic. “...and spend the night. And then I'll be on my way and we never have to see each other ever again.” 
Armen grabbed the top of the diaper and pulled himself up with all his strength. He could already smell the horrible stench of the giantess's piss. He balanced steadily on the waistband of the diaper, being careful not to fall. 
“Cadet Arlert, get a move on!” The general screamed across the courtyard. Armen jumped, losing his balance and teetering off the waistband...

and head first into Cordia's diaper.