"Shi~ Zu~ Chan!~"
I smirked, skipping towards the taller, blond man known as Shizuo Heiwajima. I saw him flinch, showing irritation, and a satisfied smile crossed my lips as he turned around, a glare clear through his purple shades. I grabbed his wrist and dragged him away, ignoring his pissed off yells and threats. The best part was, he wasn't refusing or trying to pull away. He simply followed, grumbling under his breath, and no matter how much he wanted to pull away, he didn't. Humans, especially him, are very interesting...
I threw him into the door of my apartment, where my two baby sisters sat, playing with dolls and blocks and about 500 My Little Ponies. They peered up at us, their eyes big and curious as they saw Shizuo, towering behind me and twitching slightly.
"Mairu! Kururi!" I cooed to them leaning down and scooping Kururi in my arms. Shizuo stood, adjusting his shades as he looked at us. I noticed a light blush on his cheeks, and I smiled. "Hold her," I said, thrusting her into his arms. I removed my jacket and laid it against the couch, then took Mairu and rocked her in my arms. She giggled and flailed her arms, and Kururi was staring at Shizuo.
"You're gonna scare her with that expression," I sighed, still rocking Mairu and giving her what they call a nose kiss. I laughed and bugged my eyes, and she reached forward, feeling my face. I blinked and gazed up at Shizuo, and gasped a little, my face heating at the sight.
In his powerful arms, Kururi laughed in delight. He said some random gibberish words and raised her in the air above his head, and she squealed, kicking in excitement. She reached down to his face and he laughed, lowering her so that she could remove his glasses. She played with them before dropping them back onto his face, except it went vertical on his face, not horizontal.
I was unaware of my heart slamming my chest repeatedly, and my face being a dark shade of red. He looked like such a good father... I swallowed and was snapped back into reality when Mairu shoved her hand into my nose. I grunted and continued to play with her, then sat down on the rug. Shizuo followed, sitting down next to me. I smirked at him, and he froze, realizing how much of an idiot he must've looked like. My smirk widened and he blushed, setting Kururi down and standing awkwardly. I stood as well, leaning forward and pecking his cheek.
"Babysit them for me?" I whispered, and he stuttered before nodding. I grinned and skipped out the door, leaving him with the two and secretly enjoying the sight of Shizuo and little kids.
When I opened the door later that night, I didn't exactly see what I expected...
Shizuo was leaning down with Mairu, blowing raspberries into her stomach as she laughed wildly, kicking her small legs around in happiness. She was laughing so hard I almost bust out in my own laughter. I held back and stood, my hands in my pockets as I gazed down at the 'most powerful man in Ikuebukuro' play like this with a little baby girl.
"Who's a pretty girl!? You!" He said with a gushy tone, and I held back laughter, covering my mouth with my hand to stop the leaking of any snickers or chuckles.
Shizuo sat up, smiling. He turned, his eyes meeting mine, and we both froze. I probably looked constipated from how hard I was trying not to laugh, and he looked like he just got caught by the cops in the middle of murder. After a long, awkward silence, I couldn't help but to burst out in laughter, and his face plunged into a dark, deep red.
"My, my... Shizuo!" I gasped between fits of laughter, "I had no clue you had a soft spot for little kids... especially my sisters."
"You better not tell anyone," He growled, his eyes narrowed and I swore fire flickered inside of them. "Or you'll be a dead man, you hear me, Izaya!?"
"Mm? No, I wasn't paying attention," I teased, spinning around and closing the door. I removed my coat and strode over to the kitchen, opening the fridge to get out her formula, but I saw the bottle was half empty and a bottle in the sink. A smile spread across my face. "You fed her, too? Shizu-chan, the strongest man in Ikebukuro, secretly the best babysitter around...? How interesting..."
"Izaya..." he growled from the other room, but didn't have enough time to threaten me due to the fact the two girls were getting distracted to us from their Disney movie. He made a dramatic gasp and pointed to the screen. "Look! Simba's all grown up now!" The girls stared at the screen, hypnotized, and I closed the fridge, walking over to them and sitting down next to Shizuo, who was on the couch, resting his head on his fist. I looked at him a few times, and then leaned against him.
Shizuo tensed as I cuddled myself close to him, practically forcing his arm up and around me. He glared down at me, and I smirked up at him. We made eye contact and Shizuo started to push me away.
"Ah, ah..." I whispered, leaning closer, "You'll make them upset..." I felt his heartbeat, and my own heart was speeding as I felt his warmth flood into me. I saw him blush as he turned away, pretending to stare out of the window. Instead, I leaned up, gently turning his face towards me. As soon as we made eye contact, I pressed our lips together slowly.
He froze, and I slowly wrapped my arms around him, leaning onto him and tilting my head to the side to make the kiss more passionate. He groaned softly and kissed back, until Kururi made a noise. I pulled away quickly and blushed myself, looking over to the girls, who looked extremely unhappy.
"Are you tired?" I said softly, coming over and lifting Kururi. "Shizu-chan, take Mairu..." He got up slowly and picked up Mairu, following me down the hall. Once in the bedroom for the girls, he helped tuck the two under the covers.
"I'll be right there," I said automatically, and Shizuo went directly out of the room as I hummed a soft lullaby to the two. When I was sure they were fast asleep, I quietly left the room and trotted to my bedroom.
At first, I felt like I was expecting what I saw, but then I realized it wasn't normal. Shizuo, shirtless, on his side, in a light sleep, like a husband waiting for his wife. He rolled over and saw me, and as soon as our eyes locked, my heart stirred oddly.
"I'm sorry," He grumbled, standing to get out, but I walked over, removing my shirt was well, then my pants and getting in bed. Shizuo watched me, blushing slightly, and I leaned over, turning off the light. I rolled over, facing away, and not after long, strong arms wrapped around me and a steady heartbeat hit my back. I cuddled close to the heat source, feeling a kiss being pressed into my hair.
"Goodnight, Shizu-chan," I whispered wearily.
"... Night, Izaya-kun..."

It was the next morning, and Shizuo was already awake and showered, dressed and feeding the girls breakfast. I slipped on my clothes and came over, picking up Mairu and rocking her in my arms. Shizuo adjusted his bow-tie in the mirror, made sure his clothes were tidy and came over to me, placing his hand on my shoulder.
"I'm leaving, honey...?" Shizuo froze as our faces got closer, and we stood there awkwardly. Mairu laughed joyfully as Shizuo's face darkened, and I realized I was blushing as well. He stuttered and clenched my shoulder, so instead, I leaned forward, pecking him on the lips softly and backing away.
"I'll see you tonight, then?" I hummed sweetly, and he put on his glasses, nodding slowly and turning.
"Bye..." he said awkwardly, and I returned the simple phrase as he left.
It happened fast, but as I watched him close the door behind him, I thought I heard him mutter a sweet yet short sentence. I smiled as the door closed.
"I love you too, Shizu-chan."