1. …Twilight couldn't help the smile that spread her muzzle as the teenage dragon tenderly rested the side of his head against her swollen, taut tummy. His eyes sparkled like emeralds, expression one of absolute wonder.
"I…I can feel it! Oh, wow, Twi…they're just…they're really…" His ever-deepening voice trailed off into a whisper. "They're really there."
"Well whaddya think was happening, I was just going at the hayburgers?" Twilight rolled her eyes (although the ladder half of her statement was entirely true these days). However, the lavender alicorn lowered her head towards her little brother's after taking a quick glance around, wearing a gentle and loving smile.
"Want to know a secret? A sorta Pinkie Promise sort of secret? Stygian doesn't even know yet, and I only found out yesterday." Twilight murmured, giggling lightly at Spike's bewildered expression. Silently, he crossed a claw over his heart and lay a palm over his eye. Twilight affectionately pressed the tip of her muzzle to his own snout, giving a slight nuzzle.
"You're going to have a niece."
Spike didn't respond except for blinking rapidly for a moment, then lifting his head from the pregnant mare's belly. He stared at it for a few seconds, mouth slightly agape as he rested his hands gently against her. There was another push against his palm, reacting to his touch. The purple and green dragon's eyes swiftly filled with tears.
"Hiya, princess…I-I'm your Uncle Spike. I…I can't wait to meet'cha."
And with that, a soft, small sob escaped Twilight's young friend as he ever so gently wrapped his arms around the ponies he now loved most. Twilight gave a light, weeping laugh as she lifted a wing, pulling Spike closer. The little filly inside her shifted once again, and Twilight gave a smile to the thought that she as saying hello right back to her soon-to-be uncle.
2-3. Spike, despite being in his later teens when Princess Dawn Star is born, is quick to take on the honor of designated big brother/uncle. He utterly adores the little unicorn, and is a very large presence throughout her childhood. He volunteered so much during her baby/toddler years that Twilight actually had to ask for her own daughter back at times. Though he loves each and every one of his extended family's offspring, Dawn holds a special place in his heart. Dawn, in turn, thinks that Spike is the absolute best BB/UBFF, and he always manages to make her laugh (even unintentionally).
p.s. also as you can see we're going with a slightly different design with Adult Spike in the Athenaverse. i really don't like his canon one.
Characters, MLP:FiM © Hasbro, Lauren Faust
Art © 2019