A/N: Shonda Rhimes owns every single thing. Aren't we all jealous of her? So, I've been wanting to do this for a while. Here goes.

The small child tugged the hat from his tiny head, revealing bright blond hair. Mark was becoming frustrated, but he always managed to keep his calm. Okay, not always, but most of the time. Today, he would.

"I need you to be good today," he told his son, zipping up the boy's jacket, "No hitting anyone. No painting on anything but paper. And, listen to me closely, no looking up Ms. Rivera's skirt. Daddy can't leave work to come and get you again today."

"I just wanna see what's up there." He was so adorable, Mark couldn't help but to break into a smirk.

"Well, you can't. Not until you're older."

"Do girls have boobs there, too?"

Oh Lord.

"No, Riley. They don't."

"Why do girls have boobs?" The skepticism in his voice made it obvious to Mark that Riley wasn't sure if the body part in question was a good thing or a terrible curse.

"Because they're girls. That's how they're made."

"Oh."

There. He seemed satisfied. Please, no more questions, Mark silently prayed. The questions were probably the most difficult part of parenting. He loved being a dad, really. It was a challenge to be a single parent, but after four years of managing, he had most things down to the T. He couldn't imagine life without the four-year-old bundle of joy. Ever.

"How are babies made, anyway?"

"You know what, buddy? Bailey's gonna be here in just a minute to pick you up for school. Now put your hat on."

"Why do I have to wear a hat, Daddy?"

"'Cause I don't want your little melon getting cold." Mark slid the hat onto the tiny head for the third time that morning, successfully managing to hide every lock of the blond hair that mirrored Riley's mother's identically.

When Sloane had decided that adoption wasn't the best option for her baby, she'd moved in with Mark under the pretense of allowing him to help raise the baby. Callie had offered to help, and everything had gone according to plan. For all of eight days. Sloane hadn't even named her beautiful baby when she left. Just up and out in the middle of the night, leaving her father to wake up to her crying baby the next morning.

He didn't even have a name.

Riley James Sloan. Mark had decided in an hour. Riley after his birth mother, Sloane Riley. James because he loved the name. And Sloan, because he was going to raise the baby as a Sloan. As his son. With the help of Callie, of course.

That hadn't gone according to plan for very long, either. When Arizona had received her fellowship and moved to Africa, Callie was gone, leaving her best friend to raise his grandson on his own. Riley wasn't even a year old.

No one had actually expected Mark to step up to the plate as a parent. Everyone had thought he bound to fail, himself included.

But four years later, as his son stared up into his eyes with those huge blue hues, Mark knew he hadn't failed. Despite the biological objection, Riley was his son. Mark Sloan had managed to be a father for four years. Alone. The boy filled the void women had always left him with. The boy made him laugh and cry and live. The boy was his life.

Suddenly, his thoughts were broken by a small voice, "Daddy, why don't I have a mommy like Tuck and Ella and Georgia and Teddy and all the kids at school?"

Uh oh. That one was a sincere question.

Knock, knock, knock.

Saved by the bell.

Mark stood and opened the door to see a smiling Bailey with the quiet Tucker by her side, clinging to her hand. In the last four years, the staff of Seattle Grace-Mercy West had developed a parenting family of sorts. They took turns babysitting, driving, and feeding all of the kids. Tucker Bailey was the eldest of the family, and then Riley. Next were Derek and Meredith's twin girls, at three, Ella and Georgia. Lastly, and the newest addition to the family, was Teddy Hunt.

Ironically, each of the five children was the namesake of someone else. Tucker after his father. Riley after his mother. Ella and Georgia after Ellis Grey and George O'Malley. Then, Theodore. Teddy, after Teddy Altman. Three weeks before Yang and Hunt had discovered their pregnancy, Teddy had signed on for another tour in Iraq. She died in an explosion a month before Teddy was born. The connections made the children a more active part in the hospital family.

"Alright. He had everything he needs. I have surgery scheduled for this afternoon, so Meredith offered to pick the boys up. Ella and Georgia have preschool, so she'll be there anyway."

"Fine with me," Bailey took Riley's backpack, ushering him out of the apartment, "Don't forget to check in on my post ops if I'm not there before you."

"Will do," Mark nodded, leaned down and kissed his son on the forehead, "I love you, buddy. Have a good day."

"Okay, Daddy. You too."

Waving, he closed the door to finish readying himself before he was running late.

At two o'clock in the afternoon, he had just come to the end of a partial facial reconstruction. Mark stood in the scrub room with Lexie Grey, congratulating her on her excellent work inside the operating room. Their flame had long ago died away, for reasons that only Mark knew. Well . . . Mark and one other person. One other person that would never let that little bit of information slip out.

"Excuse me, Dr. Sloan?" Turning to the face of a young female nurse, he immediately recognized the voice as that of Nancy's. She was a nurse. And he knew her name. And he had never even slept with her. It was a sad thing to be proud of, but Mark was proud of himself.

"It's your son's school. The principal called and requested that you go pick Riley up."

Great.

"Did she give you any details?"

"No, Doctor. I'm sorry. I have Mrs. Quinlan holding on line three if you'd like to speak with her."

Dragging a hand through his thick hair, he made an instant and final decision, shaking his head from side to side, "That's alright. Tell her I'll be there in twenty."

"Yes, Doctor." With that, Nancy backed out of the small scrub room.

A bright smile appeared on Mark's face as he turned back to a worried looking Lexie, "Her name's Nancy. She's Nancy and I know that. She's Nancy and I know that and I haven't slept with her. Do you know what this means?"

Slowly, hesitantly, she shook her head with skepticism.

"I used to be a man whore, Grey. I used to only know the nurses names if I slept with them. Now, I know Nancy's name. I know her name. And I know it because I care. I'm not just some dirty, sexy sex toy anymore. I mean, I'm sexy. I'm just . . . he makes me a better man." Speaking of him, Mark had said twenty minutes, "Check in on the patient when he wakes up. I have to go bail my son out of whatever he's in."

Before Lexie could say anything, he was out the door and headed to be a knight in shining armour. Not in the sense most would think, though.

The doors to Seattle Central Public Elementary School seemed small to Mark, but when he walked through them with Riley, they seemed huge. The boy had only been in school a few months, and he liked it. The problem was the fact that he was a trouble maker. Any trouble he could get into, he found and jumped on. This was the sixth phone call that had pulled Mark from work in just three months.

But he had most definitely been the same way at that age, and he'd turned out alright. Right?

Sure.

A/N: Please review. Callie will come soon. Sloan will enter eventually as well. I'm looking forward to this story, so I hope someone else is too!