A/N As a side note, I am thinking of incorporating some of the storylines of Grey's Anatomy and Private Practice into this story as it has always intrigued me to explore what would have happened if Derek was with Addison instead of Meredith when some of the major events happened. Let me know if there are any cases or events or characters that you would like to be included, and I will see what I can do!

The next few weeks after returning from LA were a whirlwind of activity for both Derek and Addison. Derek wanted to tell everyone about the babies immediately, but Addison wanted to wait. He decided not to push the issue until Addison was ready.

Addison was scrubbing out of 4 hour surgery as Derek came to scrub in. The two had barely seen each other in the last 72 hours except for brief meetings at the hospital.

Addison didn't realize it was Derek who came in as she was scrubbing. He came behind her and started massaging her shoulders.

"Oh my gosh, Derek!" Addison said jumping. "You startled me!"

"You were completely zoned out." Derek laughed. "How are you doing?" Addison looked around to make sure no one was listening.

"I can't fit into my clothes, Derek." Addison said as if it was the worst thing in the world.

"What?" Derek asked, not quite sure what Addison was getting at. She had been wearing looser clothes for about a week, but neither of them mentioned it.

"I can't fit in the spare clothes in my office." Addison said, tearing up. Again, Derek was really confused.

"Ok…." he said wiping her tears away. "I'm sorry, Addie. I am really lost."

"I have nothing to wear, Derek!" Addison said really frustrated. "A baby threw up all over the clothes I wore to work this morning, and I can't fit in the spare clothes in my office because I am 9 weeks pregnant with your twins who make me hungry all the time so I 've gained more weight than I should, and well, I have nothing to wear!"

By now Derek was trying really hard not to laugh. He knew Addison was upset

"Addie, love, why not just go naked? I definitely would enjoy the view." Derek said coyly, running his eyes appreciatively over his wife. Addison rolled her eyes.

"You and every other male in the building." Addison smirked. "You seriously would be ok with that?" she continued, seductively running her hands through his hair.

"Well, if you put it that way, then no." Derek smirked. "I want you all to myself." With that he pulled her against him and began to kiss him.

"Seriously! Can't you two keep your hands off each other for 5 minutes!" Mark said as he entered the scrub room.

"What? I have a hot wife." Derek said, briefly breaking the kiss.

"Yes, and I don't need to see what follows that kiss!" Mark said, covering his eyes. Addison and Derek slowly broke apart.

"It wouldn't be the first time you have walked in on us having sex." Addison smirked at Mark.

"As much fun as that was the hundreds of times it happened during med school and residency, I do not need a repeat!"

"A repeat of what?" Meredith asked as she walked in the scrub room. Mark, Addison, and Derek looked at each other awkwardly.

"Nothing." Mark said as he began to scrub. Meredith looked at them all for a minute and then silently began to scrub as she was assisting Mark on his surgery.

Addison pulled Derek into the hallway.

"I still don't have anything to wear." she whispered, picking their earlier conversation up.

"Why can't you wear scrubs?" Derek asked. Addison crossed her arms and raised an eyebrow.

"I have been wearing scrubs ALL day since the puking incident. I don't want the ENTIRE hospital to know I am pregnant yet. I have already received some odd looks today from the nurses." Addison exclaimed blinking back tears. "Ugh, I am so tired of tearing up so easily!" Derek gave Addison a hug. He wasn't quite sure what else to do with his hormonal wife.

"Addie, it is going to be ok. I wish I had other options on the clothes, and I am really sorry, but Mr. Kajowski really needs this craniotomy, so…" Derek trailed off.

Addison wiped the tears from her eyes. She knew she was being ridiculous but she couldn't help it. She knew it was just part of being pregnant, but sometimes she couldn't wait to feel normal again.

"I'm sorry, Derek. Of course, go, save lives. Don't worry about me." she said giving him one more quick hug. "It is almost the end of the day anyway. I don't have any more patients, so I think I am just going to head to the trailer. I am pretty tired too." Addison rambled, giving Derek a small smile.

"Why don't you book a room at the Archfield tonight?" Derek replied. "It is closer than the trailer. You can take a bath and relax. I will meet you there after my surgery….that could be awhile, so don't wait up."

"That sounds nice." Addison said, giving Derek a big smile. "Now go, save lives, be great. I will see you later." She gave Derek a quick kiss and playfully pushed him to the scrub room door.

Addison checked into the hotel room around 4:00. She looked from the bedroom to the bathroom and couldn't decide if she wanted to sleep or take a relaxing bath first. She sighed. Both sounded amazing, but as she could barely keep her eyes open, she decided to go to bed.

Addison climbed into the bed and felt like she was in heaven. The bed was so soft. As she lay there, she ran her hand over her stomach. There definitely was a baby bump. Even with the frustration of clothes not fitting, Addison couldn't help but smile at her bump. She still couldn't believe she was pregnant with twins.

Derek arrived at the hotel around 8:00. The surgery had been a success and went faster than planned. When he walked into the bedroom, he smiled as he found Addison asleep in the bed with her hands resting on her stomach. As he looked around the room, it became obvious to Derek that his wife had gone straight to bed. He quietly walked over to the bathroom and began to draw a bath.

He then walked back over to Addison, leaned over and gently kissed her. Addison's eyes fluttered open.

"Hey" she said sleepily as she stretched. "How did surgery go?"

"It went really well. I was done fairly quickly, so I ran out to the trailer to pick up some clothes for us before I came here. I also started a bath. Would you like to join me?" Derek asked, placing his hand on Addison's belly without even thinking. She placed her hand on his and smiled.

"Thank you Derek for taking such good care of us. Yes, I would love to go get a bath with you." She sat up and began to kiss her husband deeply. "Maybe we can do more than just take a bath." she winked and then jumped out of the bed and ran to the bathroom. Derek didn't need more than one invitation

The next morning, Addison woke up and stretched. She reached over for Derek to find him not there. There was a note on his night stand.

"Was paged in to the hospital. Will see you there.

Love, -D"

Addison sighed. She knew Derek couldn't help not being there, but she still missed him. She got up and decided to get another relaxing bath since she didn't have to be at the hospital for several hours.

After getting a bath and ordering room service, Addison began to pack up their things. She looked around the room and groaned. She knew she would be back in the trailer tonight. The cold, small, disgusting trailer. Derek had been talking to contractors and they were set to break ground on the house in a few weeks, but the house would take at least 6 months to build. If not longer. They would be lucky to have it done before the babies came. She knew she needed to talk to Derek about getting a house to rent. There was no way she could handle living in a trailer the rest of her pregnancy, let alone with two babies!

Addison walked into the hospital and ran into Mark in the elevator. She was feeling nauseous but didn't want to say anything to him. He still didn't know about the babies.

"Hey, Red." Mark smiled at her. "You ok? You look a little green."

"I'm ok." Addison replied, doing her best to smile. She knew she needed to get out of the elevator soon before she lost her breakfast everywhere.

The elevator stopped on the OB floor. "I gotta go, Mark." Addison said quickly trying not to run to her office. She barely made it before throwing up in the trash can. "At least no one is around to see this." Addison thought.

Meanwhile, Mark rode the elevator up to the neurology wing. He was concerned about Addison and was looking for Derek.

"Hey" Mark said as he entered Derek's office. "Your wife looked sick in the elevator. Everything ok?"

Derek looked up from the file he was looking at with concern. He wanted to tell Mark about the babies but knew Addison wasn't ready.

"I think so. I got paged to the hospital early this morning, so I haven't seen her since last night." Derek responded aloofly. Mark knew something was up as Derek didn't really seem that concerned about Addison not feeling well.

"Come on, Derek. I am not stupid. I have known you for 30 years. I can tell when you are hiding something." Mark smirked. "You are almost acting like Addison is pregnant or something." he laughed.

"Uh…." Derek stammered. He didn't want to lie but he didn't want to tell Mark about the babies if Addison wasn't ready. Mark stopped laughing and just looked at Derek.

"Dude! Is she seriously pregnant?" he asked excitedly. Derek just remained quiet. "I am guessing by your silence that she is but she doesn't want you to say anything yet. Don't worry I won't say anything, but congratulations!" Mark exclaimed, walking over to Derek and gave him a hug. Derek still was too stunned to say anything. Mark walked out of his office before Derek could say anything.

He knew he needed to go talk to Addison.

A few minutes later Derek was walking into Addison's office. The door was shut, but he went in anyway. Addison looked up startled as her door opened.

"Hey, Babe." Derek said walking over to her desk. "Mark came to see me. He said you weren't feeling good." Addison rested her head on Derek's stomach.

"I've felt better." she said smiling weakly. Derek ran his fingers through her hair. "It's just the pregnancy, Derek. I'll be ok."

"About that." Derek said, leading Addison over to her couch. "Mark figured out you are pregnant. I didn't tell him but I didn't say no either….so, he knows." Addison shrugged her shoulders.

"It is ok if you talk to him about it. He is practically your family." she said softly. " I still don't want to tell others though. I am almost 10 weeks. This is longer than I made it with the other baby…" Addison said barely above a whisper. Derek pulled her in for a long hug.

"I know you still think about that baby a lot, Addie. Just remember, it wasn't your fault." Derek said soothingly. Tears began to trickle down Addison's cheeks. The couple sat there for a long time drawing strength from each other.

Finally Addison pulled back. "I'm ok, Derek." she said, giving him a small smile. "We should probably go do some actual work before Richard starts banging down my door." she chuckled.

"Ok. I will see you later" Derek said standing up. "I have a surprise for you."

"A surprise? What is it?" Addison said following him out the door. Derek just smiled at her, turned around, and walked away. Addison knew that was his style. To annoy her by announcing the surprise and then make her wonder about it for hours. Sometimes even days.

That night as Addison was packing up her briefcase to head home, Derek popped in her office.

"So are you ready for your surprise, Dr. Shepherd?" Derek said smiling at her mischievously. Addison looked up curiously and saw Derek was holding a newspaper. Not exactly what she expected in his hands. Usually his surprises involved some sort of flowers.

"That depends on what it is, Dr. Shepherd." she responded crossing her arms and raising an eyebrow. "What's with the newspaper?"

"That my dear is your anniversary present." Derek said laughing at the reaction on Addison's face.

"Oh really." she replied slowly. Derek handed her the newspaper and couldn't stop smiling as he saw Addison's face turn from a skeptic look to sheer shock. He had handed her the real estate section.

"Derek, does this mean what I think it means?" Addison said, trying not to sound too excited.

"It means that I think it is time for us to move out of the trailer." Derek barely got the words out before Addison threw her arms around him.

"Wait." she said, suddenly pulling back. "What about the house on the property? All those plans we have been working on?" Derek smiled over her concern.

"The house won't be built for 8-9 monthis….or longer depending on the weather….and well, we obviously don't have that long." Derek replied, placing his hand on Addison's stomach. "I was thinking we could get a house or apartment closer to the hospital to live in until our other house is done. Then we can rent it out. I found one in the real estate section I think might work. It has hardwood floors, a fireplace, and it is really close to the hospital. We are scheduled to go look at it soon, so…" Derek was cut off when once again Addison was hugging and kissing him.

"Yes, Derek. Yes to all of it." Addison said happily. "Let's go look at it."

The apartment was perfect. It was large and spacious, with 2 bedrooms and 2 bathrooms. The master bathroom even had a jetted tub! It was less than 10 minutes from the hospital. It was perfect for what they needed.

As they were walking out of the apartment with the real estate agent, they were shocked to see Mark coming out of the apartment down the hall.
"Mark?" they asked in unison.

"Hey!" he said, just as shocked as they were.

"Do you live here?" Derek asked.

"I do. I just bought this apartment this morning. What are you guys doing here?"

"We are going to buy this apartment to live in until our house is built." Addison responded. They all started laughing.

"I guess great minds think alike." Mark said cheerfully. "It will be like intern year all over again! When we lived in the same building!"

"Well, let's hope it isn't EXACTLY like intern year…" Derek chided...remembering the many times Mark had told his dates to go eat breakfast at Derek and Addison's apartment because he never had any food.

"Well, I can't promise I won't be over everyday for food, but I think I have grown up enough not to send my dates there." Mark laughed. Addison just rolled her eyes. It was definitely going to be interesting living so close to Mark again.

Later that evening, Derek and Addison were sitting out on the porch outside of the trailer. The evenings were starting to get cooler, but there were still some nights where summer was trying to hold on. Derek noticed that Addison was being unusually quiet.

"Addie, are you ok?" he asked after taking a sip of his beer. Addison turned and looked at him for a minute before responding.

"Tomorrow we have been married 12 years. We have been together for almost 16. We are 37 years old." Addison said and then turned to look back out into the darkness. Derek sat quietly waiting for her to continue. "We've shared a lot of life together. Plenty of good times and plenty of bad. I guess my mother was right about at least one thing. People plan and God laughs."

Derek wasn't quite sure what to say to this. He continued to just sit there watching Addison closely. She once again turned to look at him.

"This time last year I cried daily, pleading with whatever higher being is out there to make you give me another chance. Never in my wildest dreams would I have thought it would have involved a brain tumor."

"Addie, I don't think God gave you a brain tumor to save our marriage…" Derek started to cut in.

"I know that." Addison said, talking over him. "It's just now we are expecting twins. Twins that wouldn't exist if I hadn't had a brain tumor. Twins that I have been terrified to let myself fall in love with out of fear that they would die." Addison barely choked out the last few words. Derek immediately came over to her and pulled her up into a hug.

"Addie, the babies are fine." he said kissing her temple.

"I know. And that is why my anniversary present to you is that I am ready to tell people about the babies." she said leaning back to look him in the eye.

"Are you sure? I am ok with waiting a few more weeks if you want."

"Yes, Derek. I am sure." Addison replied smiling. Derek leaned in to kiss her.

"Whose family should we tell first?" Derek asked.

"Definitely yours." Addison replied. The idea of telling the Captain and Bizzy was not something she wanted to think about yet.

Addison and Derek spent the next morning relaxing as they both had the day off.

"12 years, Derek. How is that even possible?" Addison said, shaking her head.

"It has been almost 16 years together...think of that!" Derek replied laughing.

"Are you trying to make me feel old?" Addison mocked, throwing a pillow at Derek.

"You my dear are anything but old." Derek said becoming serious. He scooted over to Addison on the bed and pulled her into his arms and began to kiss her deeply. "You are the most beautiful, sexy woman I have ever met, and I am so thankful you are mine!"

An hour later, Derek was cooking them brunch. "Would you like to call your mom after we eat?" Addison asked from her spot at the table.

"We can do that. Do you want to call each of my sisters, or should we just let Mom tell them?" Derek asked as he flipped the bacon.

"I think we should call them. They called us for every single one of our nieces and nephews...we should do the same for them." Addison said, pulling her knees up to her chest. She leaned her head back against the trailer and sighed.

"Are you ok, Addie?" Derek said turning so he could see her.

"I am, Derek, I truly am." she smiled at him contently. Derek smiled back.

After eating, Derek and Addiosn called his mom.

"Derek, how are you? Are you having a good anniversary?" Carolyn asked when she answered the phone.

"I am good, Mom. And yes, we are. I have Addison here." Derek replied.

"Hi, Mom." Addison said.

"Hi, Addison. I am actually out shopping with Nancy and Kathryn right now. Amelia is taking her boards next month, and the girls want to get her something nice. I told them we could go to Wal-Mart to find something, but they wouldn't hear of it. Apparently, doctors don't need to save money." Carolyn exclaimed.

"Well, Addison and I have some news. Can you put it on speaker phone so Nancy and Kathryn can join us?" Derek said, trying to distract his mom, as he knew she could ramble on for a long time about how wasteful his sisters were when it came to shopping.

"Oh, of course…..Girls, come here, your brother is on the phone." Carolyn called.

"So what is the news?" Kathryn asked after pleasantries were exchanged all around.

"We are pregnant with twins!" Addison exclaimed. The phone was silent for a few minutes. Addison and Derek just looked at each other. The phone was rarely silent when his mom or sisters were on the other end.

"Are you guys still there?" Derek asked cautiously.

"Yes, we are. We are all just shocked!" Kathryn replied. "Congratulations!"

"Twins! Wow!" Nancy chimed in.

"That is very good news, dears! More grandbabies to love! How far along are you?" Carolyn asked.

"I am 10 weeks today. The babies are due in April." Addison replied.

"Will you guys be able to make it out for Christmas?" Carolyn enquired. Derek and Addison again just looked at each other. They hadn't even begun to think about the holidays.

"We shall see, Mom." Derek replied elusively. "We are going to call Amelia and Liz now, so we are going to let you guys go."

"Ok. Be sure not to tell Amelia that we were shopping for a present for her!" Nancy said.

"We won't. Give our love to everyone. Talk to you soon." Addison said, smiling as Derek hung up the phone.

"What are you smiling for?" Derek asked, looking at her skeptically.

"I am just thankful to have your family as mine. That is much as they annoy you, they are a great family." Addison said, shrugging her shoulders.

"I know. You just didn't have to grow up with them!" Dered replied laughing.

They made two quick calls to Amelia and Liz, both who didn't answer, so they left messages.

"Now what about your family?" Derek asked Addison cautiously.

"No way. Not yet…" Addison replied quickly. "Let's wait a few weeks yet. Maybe when I am not nauseous all the time. But, we can tell people at the hospital tomorrow..." Addison smiled.

"Ok." Derek replied smiling. He pulled Addison in for a hug and kissed her on the temple.

The next morning, both Shepherds made their way to the Chief's office first thing.

"Addison, Derek. Happy Anniversary a day late!" Richard exclaimed shaking Derek's hand and giving Addison a hug. He was very happy to see one of his favorite couples doing better. "What can I do for you this morning?" he asked, gesturing for them to come into his office.

"Well, sir, " Addison stammered as she sat down. "We have some news to share with you."

"Are you two moving back to New York?" Richard interrupted a little anxious. He did not want to lose the dream team!

"No sir, nothing like that." Addison replied quickly. She looked over at Derek, smiled and took his hand. "We are expecting twins." she continued smiling. Richard looked back and forth between Derek and Addison for a few moments before he could speak.

"Twins? Twins?" You are sure?" Richard exclaimed surprise.

"You shouldn't be paying me so much if I wasn't sure!" Addison laughed.

"Right. Well, congratulations to you two!" Richard said laughing at himself. It was a shock to think of Addison and Derek as the parents of twins. "When are they due?"

"April" Derek replied smiling. "We wanted to let you know first before the hospital gossip mill does its work." Richard laughed.

"Yes, well. This is GOOD news to be spreading around the hospital. I appreciate you telling me first. I really am excited for you guys." RIchard said, once again shaking Derek's hand and giving Addison a hug. "Now, go save lives!" he said as the couple made their way out of the office.

Addison and Derek stopped on the catwalk after leaving the Chief's office. Derek wrapped his arms around his wife and placed his hands over her stomach as they looked out the window. They were oblivious to the group of 2nd year residents crossing on the other catwalk.

"What is up with the Shepherd's?" George asked, glancing over at the couple. He was still not used to seeing them get along, let alone showing PDA!

"Who cares!" Christina responded. "They are both McAsses! They don't have to rub their happiness in." she retorted. She still did not like Addison and Derek after what happened with Meredith. She was very thankful Meredith was not with them to see the couple all lovey dovey.

"I don't know." Izzie said slowly. "I think it's sweet. I mean, it is horrible what Derek did to Meredith, but it wasn't Addison's fault."

"She's just an ass all by herself." Alex piped in. "I have been stuck on the vagina squad forever." Just then all of their pagers went off, including Addison and Derek's.

"We are all being paged to the ER!" Christina said excitedly. "It must be something big!"

As they all arrived in the ER, Bailey was barking out orders. "A school bus crashed into a semi-truck. A high school volleyball team was on it. We don't know exactly what to expect, but we know the injuries are extensive. This is all hands on deck."

As the ambulances arrived, Owen began to direct traffic. "Derek, go to bay 1 and then bay 3. Both have severe head injuries. Dr. Sloan, go to bay 2. There is a girl with severe skin damage. Addison, go to bay 4. The bus driver is pregnant and is in really bad shape."

Addison turned and went to the room where the bus driver was as Owen continued to instruct the residents and interns where to go.

"32 year old female. Seems to be around 24 weeks pregnant. Has not regained consciousness since the accident. She crashed twice enroute. She has a broken arm and leg." the EMT rattled off to Addison.

"Thank you." Addison said, smiling at the EMT. She looked over at the unconscious woman and paused when her eyes landed on the small mound in the lady's belly. Addison's hand subconsciously went to her stomach, as if trying to protect her twins.

"Dr. Shepherd?" Karev asked, looking at Addison strangely. "Dr. Shepherd? Are you ok?"

"Uh, yes." Addison said shaking out of her trance and switching into doctor mode. "We need to check for a fetal heartbeat first." Addison continued as she placed the doppler on the woman's stomach. Soon the sound of the baby's heartbeat filled the room. Relief flooded Addison.

"The baby appears to be holding steady for now. Get her down to CT so we can see what we are dealing with. Page me as soon as you have the results." Addison handed Alex the chart and left the room.

Addison went over to the nurses station to see if there was anywhere else she was needed. Callie too walked up to the nurses station.

"You ok?" Callie asked. "You don't seem like yourself."

"I will be. This bus driver case just really got to me." Addison said. She looked around at the chaos in the ER. "I wasn't planning on telling you this way, but I guess now is as good of time as any. I am pregnant with twins. Almost 3 months." Callie's eyes got bigger and bigger as Addison relayed the news.

"Wow! I was NOT expecting that! Congrats!" Callie exclaimed, giving her friend a hug. "I can totally understand why that case is shaking you up!"

"Yeah, but I can't let it. Both the mom and baby need me at my best. I never dreamed how much pregnancy would change me."

"It seems to have changed you in a good way." Callie replied smiling.

As they were talking, Karev walked up with the lab results. Addison looked them over.

"Book an OR, Karev. This is going to be a long surgery." Addison replied, taking charge. She had to put her emotions aside so she could focus on this mother and baby who needed her. "Also, we are going to Bailey and my husband. The mother has internal bleeding as well as a brain bleed."

For the next 8 hours, the trio of doctors worked together to save the mother. They were able to stabilize her, but it was going to be a long road of recovery.

As they were scrubbing out, Addison turned to Bailey. "I wanted to let you know that Derek and I are expecting twins." Addison said smiling.

"Congratulations!" Bailey replied, a little shocked. Derek too was surprised to hear his wife telling people.

"We are very excited." Derek said, wrapping his arm around Addison's waist after drying off his hands.

"Very excited about what?" Meredith asked as she entered the scrub room. Addison and Derek just looked at each other. How did Meredith keep walking in to the end of their conversations?

"Um, well, " Derek stammered. He didn't want to hurt Meredith any more than he already had, but he knew she would find out about the babies soon. "Addison and I are expecting twins."

Derek saw the hurt and anger flash quickly across Meredith's face before she plastered on a fake smile.

"Congratulations." Meredith said and then quickly exited the room.

"Well, that could have gone better." Derek retorted. Addison just shrugged her shoulders. She still wasn't thrilled about working at the same hospital as her husband's ex-girlfriend.

"Anyway, I am really tired and ready to head home. I am glad we move into the apartment this weekend!" Addison said, yawning

"Me too." Derek replied, grabbing Addison's hand as they exited the scrub room. "Let's go get some sleep."

Let me know what you think!