For the past few days Aizen had been looking for Primera. The sudden onslaught of mating season had thrown his plans off course and now that his Primera was missing it things were taking even longer. He sighed, pinching the bridge of his nose as he sent Ulquiorra out to search again. Unlike most of the others he seemed to be in control of his biological urges.
The Quatro Espada bowed before taking off to Karakura town again. It was dark but that did not deter him, his eyes easily adjusting as he set out to look for Starrk. He searched for a good six hours when a sudden flare of mixed, powerful spiritual pressure. He followed it to its source, sticking to the shadows as not to be seen. When he finally reached the source, he was greeted with the sight of the Primera and their sworn enemy, Kurosaki Ichigo, cuddling together in the buff on their crumpled clothes. Ulquiorra didn't stay long, as he'd achieved his adjective, and quickly returned to Aizen to give him his report.
Aizen listened intently, a small smile appearing on his lips.
"So the Primera has mated with Kurosaki?" He asked.
"It would seem so." Ulquiorra replied. Aizen's grin grew wider. "Very good, Ulquiorra. You may leave." The Quatro Espada bowed and left the throne room.
"What are we going to do about this, Aizen?"
Tousan asked from his right. "Something so gravely traitorous should be punished."
"Come now, Tousan." Gin cooed from his left. "There ain't nothin' traitorous 'bout it. The puppy needed someone to help take care of his problem and the creepy kid just so happened to be willing to help." He said in his usual cheery tone. Tousan frowned but Aizen only nodded.
"Exactly, Gin. Besides, this could play in our favor. If Kurosaki has impregnated our dear Primera, their offspring will be more powerful than both of them. I could use that power to further my goals." He explained. Yes, this would work out just fine.
Back in Karakura town, Ichigo happily laid next to a sleeping Starrk. He gently combed his fingers through his brown hair and kissed his forehead, causing him to smile is his sleep. Ichigo soon fell asleep himself and found himself in his inner world just as naked as he was in the real world. He yelped as he crossed his legs and covered himself, looking around to make sure Zangetsu wasn't around to see.
"Calm down, King. The old man ain't here right now." A familiar watery voice said with a chuckle. Ichigo whipped his head around and spotted his hollow, his usual grin on his face. "Yo."
"What the hell?!" He cried as he tried to cover himself more.
"Don't be so shy, we have the same body, remember." His hollow counterpart said as he waved it off. "Besides, we have more important things to talk about, like parenting."
"...what?" He asked dumbly.
"Well you just fucked a beta in heat, wha'dya think was gonna happen?" Shiro replied.
"Whoa, whoa, whoa, what are you talking about!?" Ichigo cried, sounding slightly panicked.
"...oh yeah. I didn't tell you. Okay, so it works like this. Hollows breed like animals. They have a mating season and are split into Alphas and Betas. Since they're spiritual creatures, gender don't matter, spiritual energy does. Because you are part hollow, same with the cutie you just bedded, you're also affected by mating season. Your Alpha instincts responded to his Beta scent, you two did the dirty, and now you're gonna have little strawberry wolf babies. Any questions?" He finished. Ichigo stared at him with comically wide eyes and silently stared at him for what seemed like forever before screeching out:
"WHAT!?"
lol, I like how everyone assumed I meant Urahara