While I work on part 2 of Spreading Our Wings, I wanted to collect my headcanons on each of the Cullens' physical imperfections and the accompanying kisses.
Note: There are several mentions here of the traumas involved; references to rape and attempted suicide are included.
Carlisle has almost no hair on his left hand and forearm. Fire was his last resort when he was a newborn and he was desperately trying to end himself. He could feel his fragile control slipping away. So when he built the fire and the instinctual alarm he felt told him that he had found the answer, he was thankful. He breathed his final prayer, rolled up his sleeve, and put his hand into the fire. The months of accumulated filth burned away first, followed by the stench of burning hair. The hair took some time to burn, not being human and weak, but it finally succumbed to the flames and curled away into ash. He waited, hoping it was only a matter of time before the rest of his body followed, but in the end he was met with heartbreaking disappointment. To this day, he wonders whether he would have had the strength to tear open his own skin and expose his venom to the fire had he known to do so.
Esme wonders, too, and the answer frightens her. She kisses the bare skin of his arm not so much because of the bond they share in regards to attempting suicide, but because it's a testimony to the sort of man Carlisle is—to his courage and his determination to sacrifice himself for the nameless mortals whose lives he would have taken. She kisses the skin a little harder sometimes, fiercely grateful for the ignorance that saved all their lives that night by the fire. A very small part of her is afraid that someday, something will happen and Carlisle will make that sacrifice for her and the others in the end.
Esme apparently has some softness/leftovers from her human pregnancy, which makes no sense in canon but I like it anyway. She has a little bit of (granite?) jelly belly and she really is self-conscious about it because she's never met another vampire who has that. It took her a while to talk to Carlisle about it, not so much because of the touchy subject of her pregnancy and baby but because she felt so silly about it.
Carlisle kisses her belly to remind her that she is beautiful to him in every way. He also kisses her there because her baby remains a part of who she is and so he loves the memory of that little life he never was a part of. It took him an even longer time to start doing this, though, because he didn't want to be the cause of bringing new painful memories to the surface that otherwise might have faded away forever. He also wondered if kissing her belly might make her feel even more self-conscious, and she wasn't sure what her answer was the first time he asked. But as their love and communication grew fuller and richer, she began to love it for the meanings he had first offered her.
Rosalie has one broken fingernail, and, in a cruel twist of fate, it's her left ring finger. When she was trying to fight off Royce and her other attackers, the nail was torn on... something. She doesn't know if it was someone's face or the sidewalk or her own clothing, and she's glad she doesn't remember. Her transformation strengthened and sharpened all her nails into immortal weapons, beautiful ones. But the venom can't replace things that have been lost. When she awoke and surveyed every inch of the strange body Carlisle's poison had made for her, horrified and entranced all at once, one of the first things that caught her eye was this glaring imperfection. She asked Esme for some nail scissors, only to learn that it wasn't that simple. She spent hours, days, tearing and shaping the jagged nail with her teeth to smooth it out. She had to bite it down almost to the quick since it had been so badly torn. She thought about trimming the others so everything would match, but she couldn't bring herself to do it.
Emmett wanted to go back in time and watch Rosalie kill Royce all over again when she was finally ready to tell him about why that fingernail was different and why she has a tendency to tuck that finger away into the folds of her skirt in certain moments. He's so angry that of all people, why does she have to be the one to be stuck with something like this? He will kiss it forever, wishing every time that he could kiss away the evidence that keeps her memories so fresh in her mind.
Emmett has no visible imperfections. Not a single scar, which is honestly a miracle considering how hard it was for Jasper to not bite in those early days of sparring for fun. But Rosalie looks at Emmett's gorgeous, statuesque perfection and she imagines little changes with every passing year: human scars, graying/receding hair, new freckles—how she misses his freckles!—age spots, swollen joints... she sees, so clearly, how Emmett would change with each passing year if they lived in a perfect world.
Sometimes she kisses these imaginary signs of aging because she wishes they were real along with the fairy tale they represent. Sometimes she kisses them in half-forced gratitude that they are not there—that she and Emmett really do have forever. That he will always be young and strong and safe. To this day, she still hasn't told Emmett about her morbid little fantasy or the slowly changing pattern to those kisses. Edward thinks that's ridiculous and that Emmett would love to hear every word, but he isn't quite stupid enough to say it out loud.
Alice is forever frustrated by her hair. You just can't do anything interesting with hair this short! Why would she have ever chosen to have such a horrible, uneven, unattractive haircut?! Had she gotten chewing gum in her hair? Had chewing gum even existed back then? Ugh! She and Rosalie have experimented with all kinds of products to get as much style as they can out of it, and once she even had Rosalie try with her nails and teeth to even out the messiest spots. But it was too chaotic to really fix, especially because her hair insists on sticking out at all angles like it's trying to get away from her head—like she's just gotten some sort of shock and it's standing on end.
Jasper naturally thinks Alice's hair is the most adorable thing he's ever seen. Her hair reminds him of her visions, random and untamed and beautiful in its unique oddness. He kisses the spiky mess with gentle abandon (it's also the easiest part of her to reach) and misses the chaos when she smooths it down in a more elegant style. Of course, he can't help but love every new look she tries too. He's hopeless. But he also worries. Whenever Alice fumes about how she would never have willingly gotten an abomination of a haircut like this, he laughs and soothes her petulant fury, but he thinks the same thing and honestly, it haunts him. He remembers Maria's habit of ripping a knife through the hair of her creations as they lay there screaming in transition anytime that hair was long enough to grab during a battle. Most immortal women he encountered during those years—in his own army and among their enemies—had hair like Alice's, cropped short and sloppy. And considering how far south she had awoken and the strange circumstances surrounding her memory loss... he drew the only obvious conclusion. There's no way of knowing if her creator is still alive and fighting, and whether the valuable asset of Alice's gift had been missed. Whether that vampire might someday come looking for Alice the way Maria had coming looking for him.
So you can imagine the absolute flood of relief he felt when they learned about Alice's beginning from James, even as he shared in her grief and anger and doubt. But then he got in serious trouble when he finally shared his fears and confessed he had had them all along. That he had kept those fears to himself in order to protect her. This revelation hurt her in a way he didn't expect at a time when she was already hurting, and he would do anything to erase that mistake. They hurt and then healed together and moved on, but there will be a palpable regret in those hair kisses for a long time.
Jasper has never had a problem with his scars except for some mild worry, when he and Alice joined the family, that they might be a security risk where human notice was concerned. He was careful at first to keep as much of his skin covered as possible, especially his ravaged neck and jawline, but it turns out human eyesight and intellect are even duller than he had expected. He rarely bothers anymore, and he's glad for the warning his scars broadcast whenever they meet someone new. That warning is so rarely needed that it's almost laughable, but he still wouldn't trade it for the world. Every scar tells a story, one that brought him one step closer to Alice and prepared him to defend her and the others he's come to love.
By the time Diner Day finally came around, Alice already knew some of those stories. She had watched, holding her breath, afraid, every time Jasper went into battle and came away with more damage. But there were many more scars that were older than she was. Jasper didn't quite understand at first why she wanted to know the story of each individual scar, but he obliged, slowly baring the full extent of his violent existence to her innocent love, quickly learning to trust it. She kissed every one and kisses them still. The darkness of his past never stood a chance.
Edward has two scars on his upper back, one from each brother. The first one represents a failure: Emmett's transformation had been so disastrous that they had to keep him out in the woods, and he scented a human mere hours after waking up. The four of them tried desperately to restrain him, but it was a lost cause. Emmett tore Edward's hand clean off and grazed the back of his right shoulder with a reckless bite. Emmett got away and the human became the first of several casualties over that first year. The scar on the back of Edward's left shoulder represents a success: he and Alice were able, just barely, to coordinate and stop Jasper from killing William Cummings, a human that Edward knew personally from medical school. The fight was brief, and Jasper's bite was deep and painful, but in the end Edward was able to help him snap out of it enough to run away from temptation. The damage to his shoulder was complicated and Carlisle had to do a little vampire doctoring, causing even more pain, but the relief of saving his friend's life overshadowed it easily.
Bella thought she felt a rough spot on the smooth plane of Edward's back when she tackled him in the Palazzo dei Priori, but she didn't think much about it at the time. Near-death experiences, vampire royalty, massacres, unrequited love and all that. Later, when Edward was a little less Victorian about clothing and she was getting acquainted with his shoulders and his back, she found both the scars with her fingers even though she couldn't easily see them. Jasper had just recently showed her his own scars and given her the edited version of his history, and now Edward reluctantly told her two more tales that opened her eyes a little more to the danger she would soon pose as a newborn. Edward looked a little sick, speaking so frankly about the family body count, but all she really heard was the fact that both his scars are from times when he fought to save lives. She likes to remind him of these scars and kiss them whenever he starts talking about his monstrosity. In any case, he has a third scar now, over his collarbone, and she's the one who gave it to him in one of her more passionate newborn moments. Even he can laugh at the irony that after all his panicked angst about accidentally biting her in those first weeks, she was the one to do it in the end.
Bella still has the scar on her wrist from James's bite. She had been hoping it would disappear with her transformation so that Edward wouldn't angst over it for the rest of eternity, but no such luck. It's a physiological scenario Carlisle hasn't encountered before; his theory is that while James's venom has long since been removed, that one part of her body had already changed halfway, its cells bearing the unique ribonucleic markers of her "creator," which in turn rejected the "foreign" venom from Edward during her transformation in something akin to an immune response. Carlisle loves showing it off to anyone who will listen and she just sighs and holds her arm out while they fuss over the possibilities.
Edward cannot stand seeing the scar that will forever remind him of his failure to protect Bella. The worst part is that he knows how close he was to stopping it from happening; James had grabbed Bella's wrist and chomped down just as Edward launched himself into the air and wrenched James away a fraction of a second too late. And of course the same scar also screams a darker accusation: how very close he had come to not being able to stop when he was drinking her blood to withdraw the venom. How very close he had come to losing himself completely... this is the moment when Bella snaps him out of it and reminds him that now they both have scars from times he has fought to save lives. After a little coaxing and maybe some cute growled threats and an argument about who's more selfish, his angst is washed away. He has no choice but to kiss the inside of the most beautiful wrist in the entire world, shyly and shamefully wondering how Bella might feel about letting him bite over James's scar so that he could be the one to mark his permanent claim on her. You know, like a savage demon. Meanwhile Bella is literally four inches away, mentally screaming at him to bite her all over right now but she's afraid to take down her shield because what if she scares him? And what if he interprets it wrong? He's going to think she saw the depraved wish in his eyes and is selflessly giving him the horror-filled fantasies that he... oh, these two. They'll figure it out eventually.