All the Robin/Lucina supports put together with a little bonus at the end. You can skip it and not lose any of the plot.
Support C
"Mother, guess what?" Lucina hurried into the barracks. "I found a wonderful coat in the town market. It was gorgeous! I thought it'd be just perfect for you, so I bought it. I was thinking you could try a different style for once.
Robin smiled. "Why, Lucina! What a lovely surprise! Now let me get a look at this gorgeous" He looked up and his quill slipped from his fingers leaving a large ink blob. "Coat? Are you sure it's a coat?"
"Yes."
He took the garment from her. "Oh dear. I've never seen so many…unusual colors and shapes in one piece of clothing."
Lucina bounced on the balls of her feet. "I know! It's very modern. See all the giant pink polka dots?" She gestured to them. "If you look carefully, you'll see that each one is a portrait of Emmeryn herself!"
"How the hell did they manage that?!"
"I wager when Father sees you in this, he'll just scream with delight!"
Robin blanched. "I bet he'll scream, all right."
"Pardon, Mother? I didn't catch that." Lucina looked up from the coat and Robin quickly plastered a smile on.
'Oh Gods, I can't wear this, but I don't wana hurt my girl's feelings. Think Robin, think. You helped end an entire war for Naga's sake!'
"I'm sorry, Lucina. It's just that." He hoped he appeared regretful. "Well, this isn't exactly my…style. I'm grateful for the thought, but I don't think I can wear it."
"Oh? I was sure you would like it." Lucina's face fell and Robin felt awful. "Well, perhaps next time I go to market, you could come and pick something yourself." Her excitement returned at the new idea. "I know it seems frivolous in times like these. But in the blighted future I come from, I often fantasized of such simple pleasures."
That didn't sound half bad. "Why, Lucina. What a considerate daughter you've grown up to be. I'd be delighted to go to market with you. Delighted and honored."
"Wonderful! And when we go, I'll wear the new coat!"
Though Robin smiled, he screamed internally.
Support B
"Everyone in this town is so stylish." Lucina looked about her. She was not wearing the garish coat after all. Robin had suggested the coat be washed first and somehow it had been 'misplaced'. "I wager we'll find you the perfect outfit here."
"Er, yes. Just as long as it's not TOO stylish. Frankly, dear, you have much more." Robin quickly thought up a nice word. "Flamboyant taste in clothes than I do."
"I favor the tasteful and understated."
Understated? Yes. Tasteful? No.
"For example, what about this one?"
Robin's eyes nearly bulged from their sockets. "Gracious! I don't think I've ever seen such a…shimmery magenta."
"Hmm. I suppose it IS a little bright. Well, what about this shirt?" She held up the shirt in question.
"That's very lacy…In fact." He slid his hand under the shirt bottom. "It's nothing BUT lace. Lucina, I can see right through it!" For a moment, he had a terrible image of someone wearing this shirt with the magenta coat. That person oddly looked like Virion. The idea made him go a little green.
Luckily, Lucina had her back to him finding another coat. "How about this one, then?"
"Well, it's a nice color, I grant you, but I'm not sure about the whole octopus motif."
"Oh. I thought you liked octopi."
"I like to eat them, yes."
"This is not going well, is it? Why don't I come back another day and pick out something nice for you?"
"Er, well, I'm not sure if that's a good idea." When he saw her shoulders sag, Robin quickly added. "But…all right. Let's try it."
Lucina brightened. "Wonderful! Then I shall not rest until I find you the PREFECT outfit. Something that you will truly, truly adore!"
"Yes, I'm sure you…" Robin looked everywhere but at her. "Hmm?" A dress caught his attention. "Oh, look at this."
"Which one?" Lucina moved to get a closer look. "The baby garment?"
"Look at the tiny little bow. Isn't it just adorable?" Robin paused. "Don't you dare tell anyone I just said that." He picked it up imagining baby Lucina wearing it. She'd be the cutest little thing anyone had ever seen. "Well, enough shopping for today." He put the dress down. "We should really be getting back to camp."
Lucina hesitated glancing from her mother's retreating back to the baby clothes then back to her mother.
Support A
Robin was hoping the coat fiasco was done with when Lucina approached him with her hands behind her back. "Well, Mother, I've don't it. I've found your ideal outfit. I just know you'll love it!"
Since he couldn't see anything poking out around her, he worried what she'd found this time. "Oh, goodness. I didn't think you'd find anything quite so quickly, but, I'm sure it will be just fine. I can hardly wait to try it on!" He laughed weakly silently praying to Naga to give him strength.
"And I can't wait to see how it fits! Are you ready?" She revealed what she'd been hiding with a flourish. "Ta-daaah!"
"Huh? It's…tiny. Almost like…Lucina, these are baby clothes."
Not just any baby clothes, it was the exact same dress he'd admired.
"Yes! I saw you admiring them in the shop when we visited the market together. I didn't understand why, until I realized you must've been thinking of your daughter. The one you have in this timeline, I mean. Your REAL daughter." It hurt Lucina to say that, but she knew it was true. "You could send it to her back at the castle. I'm sure she must miss you."
"Why, Lucina…"
"I've been so happy here, despite having to fight this war. Being able to see my mother again, even if she's a he, has been like living in a dream. I didn't want to wake up and remember that you have a different life in this world." She smiled sadly. "Whenever I think of your little girl, I can't help but feel…jealous. I know it's ridiculous to envy myself, but I can't help it."
"Oh, Lucina, don't be silly!" Robin cupped her face. "I've thought of you as my daughter from the moment we were reunited! Believe me when I say I love you just the same as I love that child at the castle."
Lucina didn't dare to hope.
"When you rejected me at first, I was hurt. I admit I was envious of all the time you spent with your father, but I understood. You needed time. You are and always will be, a true daughter to me. I want to give you happy memories to make up for those you lost in your future world and I know your father feels the same way."
"If anyone knows how he feels, I imagine it would be you."
"Of course! Your father and I are alike in so many ways. We're both parents to the world's most wonderful daughter, for one." He paused. "And apparently his sappiness is rubbing off on me."
"Thank you, Mother." Lucina hugged him. "For everything." She could feel her doubts starting to lift.
BONUCE!
Robin couldn't believe he was doing this. He'd rather face an army of Risen single handedly than wear this, but it would make Lucina happy and he'd do anything for her.
He was already getting some weird looks as he walked through camp and a few snickers, but he chose to ignore them.
'For Lucina' he chanted over and over in his head.
When he entered the war tent, Chrom's back was to him so only Frederick and Lissa saw him. Frederick was doing a great impersonation of a fish while Lissa immediately burst out laughing.
Confused, Chrom turned around and stared. "Robin, what're you wearing?"
"It was a gift from Lucina." His face flushed. "I know, it's awful."
"That doesn't even come close to describing it!" Lissa hurried over. "Gods, are those dots Emm?"
"Yes."
"Why would anyone even make this?"
"It's not awful." Chrom interjected. "I rather like it."
And that explained Lucina's…unique fashion sense. Robin owed Gaius some money it seemed.
Thinking of Lucina….
She pushed the tent flap open. "Father, have you." She spotted Robin and clapped her hands like an excited child. "You're wearing it! What made you change your mind?"
"I decided it wasn't fair of me to judge the coat without actually wearing it."
"Doesn't Mother look amazing, Father?"
Lissa had moved back to Frederick and had to bury her face in his bicep to keep from laughing. Her whole body shook with the effort.
"He does." Chrom nodded. "The pink seems a bit much. Maybe if they were a different color? Emm usually wore greens and whites."
"That's a great idea!" The future princess tapped her chin. "I wonder if the tailor is open to that suggestion?"
Frederick considered it. "Why wouldn't be? His product will have the royal seal of approval. Everyone will be clamoring to get their hands on one." Another thought came to him. "Perhaps this tailor would be willing to create such garments with all the royals' portraits."
Lissa pulled back looking up at her future husband in horror. She did not want her face in a neon pink polka dot!
Chrom didn't seem too keen on the idea either. "Ah, Frederick, that might be taking it too far. I don't need things commemorating my rule yet."
"Plus we wouldn't want to accidently over shadow Emm's tribute." Lissa quickly added. "There's still plenty of time for us to come up with something original for us."
Lucina frowned slightly. "Yes, I see your point, Aunt Lissa." It was a shame too. She would have really liked a dress with little portraits of her father on it and a matching shawl with her mother's portraits.
Robin groaned rubbing his face. This was getting way out of hand. Humoring his daughter was turning out to be a nightmare.
"That's reminds me." The blue haired girl brightened turning to her parents. "When you two were married, was there any memorabilia created to honor it? I'm afraid I was preoccupied at the time to take notice."
Frederick seemed to preen. He'd helped design some of those. "There was indeed. All finally crafted. I'd be happy to show you."
"You would? Thank you, Uncle Frederick! I'd love to see them."
The married couple groaned in unison. Anything but those!
"I told you you should have let me burn them." Robin grumbled.