Friendly suggestion... grab some tissues.
Gaster
Gaster rubbed your back gently. You were doubled over the toilet, blood mixing into the water as you coughed violently. His soul ached with pain as he watched you, unable to help in anyway.
His nights, when you slept, were spent more and more in his lab as he frantically searched for a solution to your ailment. Whenever you were awake he spent with you. As you grew weaker you found yourself bed bound you and Gaster were unable to hide the truth from the boys. They had become painfully aware that something was wrong.
They had approached Gaster on multiple accounts, always with the same question 'What was wrong with Mommy?'
Gaster was never able to give a straight answer until one evening it become evident they deserved a true answer.
He sat them down on the couch while you slept.
"Boys, _______ is... ill."
Papyrus looked shocked, "B-but Mommy will get better soon right?"
Gaster couldn't bring himself to meet Papyrus's eyes. Sans though seemed less shocked than his brother. He still seemed to be filled with disbelief however. His expression was somber as he answered in Gaster's place, "I-I don't think she is, Paps."
Tears formed at the corner of Papyrus's eye sockets as he looked between the two skeletons both avoiding his gaze, "N-no... t-that c-can't be true... D-daddy, say its not t-true."
Gaster finally met his sons eyes, his own pained. Papyrus hiccupped as tears trailed down his cheekbones. Gaster embraced his sons, no words were passed as all three stayed in silence, the only sound was the sobs of the three broken males.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
Reader
A cold sweat had broken out along your brow as you shivered beneath the sheets. Gaster was holding your hand as he wiped a cool towel along your forehead. You had become smaller as the third week commenced, your limbs were weak and you found yourself lapsing into bouts of pain every so often. You gripped Gaster's hand using it as an anchor to the world. You would have laughed at that if it hadn't been quite true- and if it didn't hurt to do so.
You stared up into your husbands eyes wishing you could drown out the pain by disappearing into those eyes forever. Gaster stopped wiping your brow and rose to leave. You held onto his hand, willing him to stay.
"I need to go, _______. I need to return to my lab," Gaster told you, his face melancholic.
"Please don't leave me," You whispered, your voice hoarse.
Gaster looked torn as he looked into your pleading eyes. "I-"
"Gaster, I-I don't want to waste any of my time without you," You told him.
He swallowed and sat back down on the edge of the bed as he stroked your face, "I don't want to lose you."
You brought your arm up to weakly hold his to your face, "I'll be with you no matter what Gaster..."
A light purple shimmer appeared at the corner of Gaster's eye as it formed into a almost clear shape that slid down his cheek bone.
Tears
You realized. Raising an arm with a great amount of effort you wiped the tears gathering away. Gaster moved his face to lightly kiss your knuckles.
"Stay with me," You told him.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
When you awoke again you saw Gaster had fallen asleep beside you in a chair, his hand entwined in your own. You lightly stroked his cheek.
A noise caught your attention. Turning your eyes to the door you saw the small shape of a skeleton approach.
Sans stood beside the bed, quiet as to not awake his father.
"Sans," You breathed.
His face was solemn as he watched you.
"You know you broke our promise..." He spoke quietly.
You met his eyes, "I'm sorry..."
There was a small 'plip' sound as a tear ran down his face, landing on the carpeted ground.
"You can make it up to me by getting better."
"I-I don't think I'm going to get better," You spoke, knowing very well that it was the truth. It hurt to admit it.
More tears trailed down his face as he came closer, "T-then who's going to be Papyrus's Mommy? W-Who's going to be my M-mommy?"
You felt tears form in your eyes, "I'll always be your Mommy, Sans... unless you don't want me to be."
The little skeleton sniffed as he broke down completely. You embraced him as he leaned into your body, his shoulders rocking with each sob, "I-I want you to be my Mommy."
You felt your own tears rush down your cheek as you and Sans hugged, both releasing feelings that had been buried deep.
When you both finally calmed down, Sans pulled away. His eyes were dim and tears were still leaking from his eyes. He turned to leave, looking back only one more time before disappearing through the doorway.
~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~
The next time you awoke Gaster was awake, Papyrus was curled up in his lap. Seeing you awake the small child smiled, "Mommy!"
You smiled faintly at Papyrus. "Hello, Papyrus. How are you?"
"I am very good... Are you feeling better Mommy?" He asked, worry evident on his innocent face.
"Yes, seeing you makes me feel so much better," You told the child, ignoring the welling pain in your abdomen.
"T-that is good. I will visit more often if it makes you feel better. How about I bring a book tomorrow and I will read to you!" Papyrus declared.
You smiled weakly, "T-that sounds very nice..."
Gaster noticed how weak you sounded, "Papyrus, why don't you go help your brother clean up downstairs."
Papyrus looked up confused at his father, "O-okay..." Climbing out of his father's lap Papyrus kissed your forehead before leaving with a quick farewell.
"I'll come read to you tomorrow Mommy."
Then the little skeleton was gone.
Your smile slipped as you closed your eyes, pain rippling through you. Grasping Gaster's hand you moaned in pain.
Gaster looked shaken as he gripped your hand in both his hands.
"_-________," He whispered.
You swallowed back the pain and smiled up at the terrified skeleton.
"I-I'm fine... j-just a little pain," You told him.
Gaster nodded, "I'll go get you some water."
Gaster
Gaster went to rise but was stopped as you gripped his hand, not letting go. Your grip was weak but he stopped.
"_-______?"
He turned back to face you, your eyes pleading for him to stay. Something within him broke.
N-No...
Your eyes were shining with tears, "G-Gaster... stay with me."
Gaster sat back down, leaning in as close as possible to you.
"I-I'm here," He told you.
Your hand stroked his cheek before falling to the bed as winced in pain.
You smiled faintly, "I-I think I'm going to miss P-Papyrus's s-story."
Gaster choked back the emotions that threatened to bubble over.
"I-I love you so much G-Gaster," You told him.
Part of him broke.
"I-I love you too, __________."
Gaster swallowed as tears threatened to fall.
"D-do you remember when you insisted you felt like a genie," He spoke, trying to keep your attention on him as your eyes started to mist over, seeing things far beyond his sight.
Smiling you nodded as best as you could, your eyes flickering however your eyes trained on his own and did not move from there.
"W-well I did my research. Apparently if you find a genie you get three wishes. I found you, and you are my genie are you not... therefore I believe you owe me three wishes," Gaster stated wavering.
"N-now you believe in genie's," You spoke amused, your voice losing its strength.
"Why not, you are a genie are you not," Gaster's voice cracked with emotion. "Therefore I have three wishes, the first is that the barrier be broken so that you can take me to all those places you told me about... like Paris and Berlin... the second is that we find a nice little house somewhere you, me, Sans and Papyrus can live."
Your eyes drooped as Gaster took your spare hand into his face and lifted it to his cheek, tears blurring his vision, "A-and the last... is that you and I live together forever, happily, as if none of this ever happened."
Smiling you breathed, "I-I like t-that w-wish."
Gaster didn't notice the tears as they trailed down his face. What he did notice was the lights in your stunning eyes as they diminished. He noticed the stillness of your chest and the lack of laughter that once rang from your perfect lips . He noticed the limpness of your arms as they fell away from his face and he noticed the final breath that held the force of your life as it left your being.
He didn't remember how long he remained by your side. He did remember calling your name over and over as he ran his hands through your hair, holding you close to his chest as his soul broke into infinite pieces. He remembered that when you left him you took his soul and his heart with and left his him empty and broken.
I-I'm not crying... I'm totally not crying I just got something caught in my eye....
Two more chapter left guys. An alternative ending (?) and the epilogue
I'm going to go hid under my blankets... and totally not cry.