A/N

Sorry I took so long to update. This chapter is long to make up for it. It took me a while to figure out this but I did it! I love this chapter so much. It's definitely one of my favorites. I was trying to decide whether Scarlett should be with Luke or Marvin, but in the end, I decided Marvin. There's a five-year age gap between them, but compared to the six-year age gap between Ted and Tracy, I figured this was fine. This is pure fluff and I love it.

Mary's Song

And our daddies used to joke about the two of us. They never believed we'd really fall in love.

2040

Robin couldn't believe where she was. She had already had to pinch herself multiple times today, to make sure this was real and this was happening. She now stood beside Barney, leaning on him as they watched their little girl. Maggie put the mascara wand down, impressed with her work. The door opened and Lily stepped in, jaw dropping when she saw her soon to be daughter-in-law. Scarlett turned around from the mirror, to face her parents and fiancée's mother.

"You look just like your mom, Scar." Barney said. She smiled and reached in to hug both her parents. As they broke apart there was a knock at the door. Twenty-six-year-old Daisy and twenty-five-year-old Penny entered.

"Woah, Scarlett! You look amazing." Penny said.

"Drop dead gorgeous." Daisy added.

"Aww thanks guys." Scarlett said with a smile. She reached out to hug her bridesmaids. Maggie, who was her maid of honor, quickly jumped in to join the hug.

Lily pulled her iPhone out. "Let me get a picture." She snapped a picture of the four grinning girls.

As they were admiring the photo and comparing it to one taken twenty years earlier, there was a knock at the door. Luke stepped in.

"Ladies, Uncle Barney. The ceremony is about to begin." He said. Everyone bustled out of the room and followed Luke to the ballroom. The room was already filled with people. At the end, in the front row, Marshall was sitting beside three empty seats. Marvin was standing nervously at the end of the alter. Luke buzzed past everyone and went to fulfill his duties as best man, by standing next to the groom. Lily followed Luke and went to take her place in the seat next to Marshall.

"Good luck, baby girl. I love you so much." Robin said, kissing Scarlett on the cheek. She smiled at her mother. "And good luck, babe. Don't trip over on the way up the aisle, okay?" The final sentence was directed at Barney. She spun to head up the aisle.

"Robin!" Barney stage whispered. Everyone was talking too loud to hear him though. She turned around to face her husband. "Where's my kiss?" She rolled her eyes. Somedays it feels like she married a twelve-year-old. She pecked him on the lips and then went to sit next to Lily.

Music started playing and Penny, followed by Daisy and Maggie made their way up the aisle. Barney entered with Scarlett on his arm and grinning widely. He got to the alter and Marvin stepped forward to take Scarlett's arm. Barney wouldn't let go of her.

"Dad." Scarlett hissed.

Robin took her husband's elbow. "Barn."

"Sorry." He whispered to Marvin and Scarlett. He released his daughter's arm and sat down beside Robin, taking her hand.

...

"I now pronounce you husband and wife." The priest announced. Scarlett grinned and threw her arms around Marvin as they kissed. When they let go of each other, Marvin turned around to hug Luke and Scarlett spun around to hug Maggie, Daisy and Penny. Barney pressed a kiss to his wife's temple, reminiscent of their own wedding day. That was twenty-seven years ago. Now, their daughter was twenty-three and married. As he watched Scarlett laugh and kiss Marvin again in celebration, he wondered where the time had gone. It seemed like she had only been a baby, laughing when they tickled her toes, yesterday. The last twenty-three years were a whirlwind of her milestones. Talking, walking, starting school, first kiss, driving, going to prom. But, he wouldn't trade any of it for the world.

Later, at the reception, Barney, Robin, Ted, Tracy, Marshall and Lily were all seated at their table. They were laughing and exchanging memories while they watched their kids at the table next to them, eating.

Lily giggled, clearly having had a little too much champagne. "I'm gonna make a toast." She stood up and tapped her fork against a glass. "Hey everyone! Okay, first, I want to say thanks to everyone for being here for Marvin and Scarlett. I know it means a lot to them. They're a beautiful couple. My husband, Scarlett's parents and I are going to share a few of our favourite memories of the two of them from over the years-"

Robin cut her off. "We're gonna do what?"

"Share memories, Robin. Just do it, okay? Anyway, they've known each other since Scarlett was born, so I'll just start from then. Marvin was five and Scar was a newborn."

August 2017

Lily was beyond thrilled as she entered the hospital. She couldn't believe Robin and Barney were parents. Yesterday, at around midday, Barney had called her to say they were at the hospital, and she had been awake for the better part of the night waiting for him to call and tell her he was a dad. Finally, around two am, he had. She, Marshall and the kids had come straight to the hospital as soon as visiting hours were open.

"Guys, we're gonna have to be quiet okay? If Aunt Robin, Uncle Barney or the baby are asleep, you can't wake them." Marshall informed his kids. He shifted three-year-old Daisy, who was sitting on his shoulders.

"Ok." Marvin said, dropping his mom's hand and running ahead. The two had left eight-month-old Maggie at home with Mickey. She would just be trouble in a hospital. They reached the Stinson's room and Marshall pushed it open gently.

Inside, Barney was seated in a chair, transfixed on his daughter's eyes. Beside him, Robin was fast asleep in the bed.

He looked up when he heard the door open. "Shh." He placed a finger over his mouth. He was unbelievably proud of his wife, who had just suffered a nineteen-hour labor and deserved to sleep.

"Hey daddy!" Lily whispered. Barney glowered. Marshall pulled up two chairs and he and Lily sat in them, pulling Daisy and Marvin onto their laps. "She's gorgeous." Lily remarked, looking at the baby girl in Barney's arms.

"Course she is. She looks like her mommy. Besides, have you seen Robin and I? How could two unbelievably hot humans not make an adorable baby?" Barney smirked. Lily rolled her eyes. Scarlett cooed and Barney's heart visibly melted.

"Can I hold her? Please?" Marvin begged.

Barney wasn't super pleased with the idea of letting someone else hold his baby girl, but knew Marvin was good with this. "Sure buddy. Just sit on your mom's lap, okay?" Marvin scampered onto Lily's lap and held his arms out. Barney got up and gently put the bundle into his nephew's arms. He kissed Scar on the forehead and stepped back.

"She's so small!" Marvin giggled. "Hi baby. I love you." He copied Barney's action of kissing the baby on her forehead and Lily thought her heart might burst of happiness.

Back to the present- 2040

The audience awed as Lily finished her story.

"I know right!" She said, content with the reaction. "Okay, Marshall's next."

He thought for a second. "Ok, let's skip to the Fourth of July 2020. Marvin was eight and Scarlett was almost three."

July 2020

"Happy Fourth of July, everyone!" Barney yelled as he walked through the side gate of Ted and Tracy's house.

"Fourth a July!" Scarlett repeated. Barney grinned at his daughter who was resting on his hip.

Lily stepped forward and took the toddler from Barney's arms. "Hey Scarly!" She cooed. Barney smiled and went to put some food they had brought on the table.

Robin appeared at the gate holding multiple bags and plates of food. "Thanks for the help, babe." She sneered sarcastically. Marshall and Tracy quickly took platters from her arms before she dropped them.

"Sorry." Barney replied, pacing over to her and kissing her temple.

Scarlett batted her legs against Barney's stomach and back. "Daddy, I wanna go down!"

"Ok, bossy." Barney said, letting her go.

"She's got a good vocabulary for a two-year-old." Ted commented.

"Yeah, Luke's only eight months older than her but she's better at talking." Tracy added.

Barney and Robin smiled and everyone went to sit back down on the deck chairs. Their eyes wandered and they watched the kids playing. The six children were piled on the trampoline. Daisy and Penny were jumping around and trying to push the other one over, while Marvin scolded them whenever they got too close to one of the younger kids, specifically Scarlett.

"DADDY!" Penny suddenly bellowed.

"What's wrong, Pen?" Ted asked.

"Can we go in the pool?" She questioned.

Twenty minutes later, all the kids had changed and floaties had been put on the three younger kids. Being Canadian, and supposedly used to cold temperatures, Robin had been forced to get in with them, to make sure nobody drowned. It was the middle of summer and the pool was actually quite nice, but she played it off to be freezing because she was annoyed that she was the one who had to get in.

"Aunt Robin, watch me!" Maggie squealed as she threw herself into the pool. Robin was splashed with chlorined water as the three-year-old plunged in.

"Babe, take her." Barney said as he dipped Scarlett's toes into the pool. Robin reached forward and took the two-year-old from her husband's grip. As she was adjusting her, Luke freaked out and started splashing everywhere once he couldn't touch the bottom anymore. Robin handed Scarlett to Marvin and swam over to rescue her nephew. Marvin swept Scarlett onto his shoulders. She giggled.

"Watch this, Scar." Marvin said. "Hold your breath." He dove underwater, holding her in place on his shoulders. They both emerged laughing and Scarlett chanting more.

Back to the present – 2040

"Ok, Robin's turn." Marshall immediately said as he finished his story.

"Um, I guess let's do the back to school party 2022." Robin responded.

September 2022

It was the end of an era. There were no more babies in the gang. Scarlett, Luke and Maggie would be starting school in two days. Tracy, Ted, Marshall, Lily, Barney and Robin were sitting on the lawn at the Mosby's house, balancing plates of hot dogs, French fries and coleslaw and watching them all playing tag.

Lily sniffed. "No more kids left."

Robin looked up. "There are literally six children over there." She gestured in the general direction of where the kids were playing and then turned her attention back to her food. She leant over and stole a fry from Barney's plate.

"You know what I mean. They're all growing up." Lily replied.

"If you want babies so bad then have another kid." Barney advised.

"Hell no. That ship sailed a long time ago." Lily said. "Can you two have another baby?" That was directed to Robin and Barney.

Robin almost choked on her food. "What!"

Lily looked at her like she was asking a terribly simple question. "Can you and Barney have another kid?"

"Uh, no. No, that's not happening." Robin stated.

"Why?" Lily whined. "You already have one, it wouldn't change your life that drastically."

"Yeah it would." Barney stated. "Robin and I aren't like you. We don't sit around and plan our life. We just live it. If she were to get pregnant again, I wouldn't be opposed to being a father again, obviously. But we're not going to start trying or anything. I'm happy with my girls, I don't need anything else."

"But they're all growing up so fast! Soon they'll be in college and then married and having babies and moving away and never calling us! Then they'll put us in nursing homes and we'll die!" Lily wailed.

"Dramatic much." Tracy said, stifling a giggle.

"I wonder what their lives will be like. Will they get married? Will any of them marry each other?" Ted asked, curiously.

They all watched the kids intently, wondering. They all had water guns and were shooting each other and squealing. Daisy was holding Luke's arms behind his back while Penny squirted water onto his face. Maggie was shooting at Scarlett and she shrieked and took cover behind Marvin.

"Maggie and Luke would be cute together." Robin observed.

"Maybe. Is any of them marry within the inner circle though, my money is on Marvin and Scar." Marshall announced.

"Dude! That would be so awesome! Can you imagine how amazing Stinson and Eriksen DNA would be mixed together?" Barney shouted.

"SO AWESOME!" Marshall replied.

"WE COULD GET A GRANDSON! HURRICANE WAITFORIT ERIKSEN!" Barney screamed. Lily and Robin caught each other's eyes, smiled and laughed.

Back to the present – 2040

"Ew. You guys thought I would end up with Maggie?" Luke asked, clearly disgusted.

"Aunt Robin did." Marshall offered. "Now it's Barney's turn."

"Easy. Marvin's fifteenth family birthday party. Scar was nine going on ten." Barney smiled.

May 2027

"…to you!" Everyone finished singing. Marvin leant over and blew out the candles. Everyone started clapping and Lily went off in search for a knife. She found one and handed it to her teenage son. He cut into the chocolate cake and pulled it out.

"You touched the bottom! You have to kiss the nearest girl!" Maggie squealed. She, Penny and Daisy darted off to the other side of the room. Lily stepped closer, expecting him to peck her cheek. He didn't.

"Sorry mom." He stated. Marvin lent to his right and kissed Scarlett on the cheek. It took her by surprise and she blushed. He turned to his left and kissed Robin's cheek before turning back to the cake and cutting slices.

Barney narrowed his eyes at the boy. "I'll get you Eriksen. That was both my girls. My wife and my daughter." Marvin grinned and handed him a plate.

He finished cutting the rest of the cake up and served them onto plates. He handed them to Maggie, Daisy, Penny and Scarlett.

"You have a crush on Marvin." Penny teased, grinning at Scarlett.

"No I don't!" She squealed.

"Yeah, that's why you blushed when he kissed you." Daisy offered. Scarlett dumped the plate on the table and ran into the bathroom, slamming the door shut behind her and locking it.

"Daisy!" Lily scolded. "You're thirteen years old, don't tease your cousin. You should know better."

"Robin locked herself in that bathroom too." Marshall laughed, attempting to lighten the mood. Robin ignored him and went to the door.

"Scar? Honey, come out." She called, knocking lightly.

"NO!" The nine-year-old yelled from inside.

"Not cool Daisy. You neither Penny." Marvin said. He dropped his plate on the table and went into the front yard. He etched open the window and climbed inside. "Hey." He said to Scarlett.

"Go away." She sniffed.

"Don't listen to them, okay? They're stupid. I know you don't have a crush on me." He said. She nodded and hugged him.

Back to the present – 2040

"I totally had a crush on him." Scarlett laughed. Marvin smiled and kissed her.

Marshall lent forward. "By the way, you guys owe me five hundred bucks each. Told you they'd end up together."

"We didn't bet on that." Robin said.

Marshall shrugged. "Worth a shot."