Castle of the Two Sisters
Smolder landed and groaned as she felt her body heat up at the thought of what she was doing. More importantly was who she was doing it for. If Smolder was being honest with herself, she kinda saw FrostBite like a brother. Which made how she was feeling that much weirder.

Groaning, she looked off to Ponyville then to where she heard Appaloosa was. She had time. She had to have time. This was a matter of do or… well. She'll cross that bridge when she gets to it. With a huff, Smolder took off again.

Upstairs in FrostBite's home
Twilight and Fluttershy finished cleaning Scootaloo. Pulling back Twilight looked at her friend who was smiling softly at the pegasus. "Fluttershy? Do you know what happened?"

Fluttershy shook her head. "No. But if I had to guess? When FrostBite was-"

"Welcoming her into the herd…" Twilight quickly interjected. She didn't really want to have to many thoughts of her friends or their families having sex with him. She knew it'd raise questions, and she'd want answers. Which will end up turning her on. And that would end in only one thing at that point.

"Ummm… right. Well…" Fluttershy thought of how to put it. "Maybe whatever caused your brother and Flash to change, made her grow… that." She motioned to the monster that Scootaloo was sporting.

Twilight looked at it and blushed. "I'm sure she'll be surprised when she…" just then it dawned on her. "MY BROTHER WHAT!?!?!?!"

"Oh my." Fluttershy sighed as Twilight rushed out the door.

In the Livingroom
Gleaming and Glitter helped with whatever Applejack instructed them to. Moments later Twilight bursted down the stairs and scanned the room. At the sight of her "brother" she gasped. "WHAT'S THE MEANING OF THIS?!?"

"Oh Twily!" Gleaming cheared, sporting a pink silk choker.

"Don't Twily me. What's going on? I thought you were married to Cadence. How could you do this to her?" Twilight snapped.

Gleaming took a deep breath. "Twilight. I do love her. Always will. But the truth is… our wedding was a political one."

"What?" Twilight gasped.

"Think about it. The most time I spent with her was when she came to look after you. And that was at most five minutes each time. Even the guys at the barracks knew we wouldn't last." Gleaming explained. "If it wasn't for our parents… I probably wouldn't even have ended up marrying her."

"But… but… FlurryHeart… what will happen to her?" Twilight asked.

Gleaming sighed. "We'll tell her in time. We both still love her. But we… unofficially at least. Are no longer together." Seeing her little sister about to have a meltdown, reached out and pulled her into a hug. "Besides. Who's going to help take care of YOUR kids?" She teased.

Twilight giggled and returned the hug. "There's plenty of help here already. But it's still nice to have you around." She thought for a moment then asked. "This might be strange but…"

Gleaming shrugged. "I was a bit overcome with… well…" She thought for a moment. "I think I'm his bitch."

Twilight blinked. "I… need to do some more research on this." She sighed. As if to answer her, Gleaming levitated over a book. "Thanks." She sighed, before opening it. "Herds for beginners." She chuckled. "Let's see… starting a herd… joining a herd… oh, here we are. Roles and… advancement?"

"There are several roles one can get in a herd." The chapter began. Twilight quickly skimmed past the parts she had figured out. "The most common roles are: mates, caretakers, workers, and breeders." Twilight nodded in understanding. "While the first two are widely used, the other two have in recent time been divided into other roles." This perked Twilight's attention. "The role of workers for instance can be seen as job holders or relief partners. Meaning that one would be responsible for financial obligations and the other being there for rutting."Twilight blushed in realization at what this meant for some of her friends. "As for breeders, this category is divided into a more personal grouping. Pets and sluts are two widely used groups. Pets are considered among the highest in the herd next to the alphas. While sluts are used for anything the herd needs." Twilight gulped and looked at her new sister for a moment before returning to the book. "Very few may be given a new role by the alpha. However, the highest they can go is a pet. And be warned that just as one can advance. It is far easier to be knocked down in roles."

Twilight took a deep breath and closed the book. She had one question on her mind. And she feared asking it. "What are our roles?"

???
FrostBite laughed as he held Rainbow close. "I'm glad you survived Rainbow." He sighed. "I thought I lost you."

Rainbow's smile faltered for a moment. "FrostBite? Who's that?"

The two looked over to the shadows as Luna stepped out. "Luna? Wait… does that mean???"

"You are dreaming." She replied. "But I did not want to disturb you. I thought you needed this bit of hope. So I let it proceed."

"Then why come now? What do you want?" FrostBite asked.

"I have news on Rainbow. She is holding on. And may make a quick recovery. But if what your dream shown is true. Then we are running out of time." She warned.

It didn't take much for FrostBite to figure out what she meant. In his first few days in the dragon lands, he was close to death himself. And now, Rainbow Dash, his Ruby, his mate, was facing the same fate. With a nod he lifted a claw to his mouth and bit hard.

Lava Pool room
FrostBite sprang up with a jolt. After spitting out his claw, he turned and rushed to Rainbow as the nurse put a fifth blanket on her. "Sorry sir but-" the nurse started. She let out a gasp and shrieked as he took Rainbow in his claws and dove into the pool. Seeing the two vanish into the lava, the nurse promptly passed out.

Author's Note

As requested. Here's the list of herd members and their confirmed roles up to this point:

FrostBite: alpha male
Rainbow Dash(Ruby): alpha female
Scootaloo: second pony mate
Applejack: pet (possible worker)
Fluttershy: pet (likely caretaker)
Sunburst: SLUT
Shining(Gleaming) Armor: slut (possible relief partner)
Flash(Glitter) Sentry: worker/relief partner
Sunset Shimmer: pet (definitely breeder lol)
Gallus: bitch(one small step up from slut)
Sandbar: slut
Ocellus: slut (hungry pet?)
Silverstream: pet
Twilight Sparkle: ???(maybe worker?)

All other ponies have either left or have yet to join. May have Yona join soon. Any other ponies care to join? Lol