Tia(F Mega Latias) X Tio(M Mega Latios)

After finding their mega stones, Tia has been wondering why her brother has been being distant from her, so she decided to find him and found his reason as well.

Tia was flying through the sky, wondering where her brother is. 'Where is he?' she sighed inside. She felt something weird about him. She held her mega stone to her face as this started when they found them and were able to mega-evolve. He grew distant for some reason and she didn't understand why. 'I have to know what's wrong with him!' she said inside as she uses her mega form abilities to track her brother. She found his signature and flew as fast as she could.

She arrived near a forest next to a waterfall, before Tia went closer, she turned her body invisible so he wouldn't see her. She floated above the ground and slowly went forward. Tia heard him moaning nearby so she headed near a brush in the bushes and moved them away to see. She blushed as he was groaning while rubbing his cock. She also notice that her Tio was in his mega form as he does this. She tried to stay silent as he kept couldn't blame her brother, she knew he was close to his puberty before. She turned around and was about to leave.

"Tia." groaned Tio. Tia froze in shock, fearing that her brother found out she was there. "Harder." groaned Tio moving his hand faster. 'Huh?' Tia thought as she turned to him again. He seemed to be panting even harder than before. "Oh Tia." Tio said with a pleasured filled moan as he pumps Tia blushed as she realized he was masturbating to her. She was shocked but was touch to see that her brother had feelings for her and wondered why he kept this to himself all this time.

Tia felt a drop from her neither regions and went to see that her slit has become puffy and wet from her brothers moaning and moved her hands to open it a little more. 'Wow it looks cute.' she thought to herself with a giggle as she starts to rub it with her right arm and fondles her breast with her left, masturbating like her brother is. She slowly began to feel hot as she tried to match her brother's rhythm. Her breathing begins to match her brothers as the pleasure overtakes her as well. Soon they both reached climax and sprayed out their seeds. Tio's seed reached a distance while Tia's juices drenched the ground. Both pant as they recover from their orgasms.

As Tio was catching his breath, he caught a strange scent in his nose. He raised his nose and took another sniff. 'Why does this smell familiar?' he thought as he tries to recognize the smell. Tia saw him sniffing the air and realized her pheromones must be in the air. The look of shock and realization on his face proves that.

With that, Tia moves out of the bushes and deactivated her invisibility, appearing in front of her brother, Tio jumped at seeing his sister reappear. "T-Tia?" Tio said out loud. "Yeah, it's me." she said to him. Tio looks to see his hand still at his cock, which he moves it away from his cock. "I'm sorry, I needed some release." he said with a blush, hoping not to dig deeper. "It's alright, same here." she admitted looking away. Tio looked surprised at her answer as he looks at her. "Y-you were watching, h-how long?" he ask with a increasing blushing face. "Since the beginning." Tio starts to get covered in cold sweats, "Then you heard...?" "Yes." she nodded.

He starts to panic cause she knows why he was masturbating, "I...I..." "It's okay. You want to be my mate right. Alright then." "Wait, what?" asked Tio. "We can be mates." Tia repeated. "Even though we're siblings?" he asked. "Yes Tio, I love you." Tia said sweetly as she went and kiss him. Tio's eyes widened at feeling his sister's soft lips against his. He soon started kissing her back as he wraps his arm around her body. Tia smiled as her chest pressed against his chest. The two kept making out for some time before separating to catch their breaths. 'You're really good with your tongue.' she said to him mentally. 'Thanks.' he grinned. 'You weren't bad yourself.' he told her.

He started to place her on her back and moved so he's at her wet folds. "So pink." he muttered. He gave it a few licks for her flavor. "AH!" she gasped and arched her back. When she does this, Tia caught the sight of his shaft already hard again. He delved deeper and pushed his tongue into her folds. She moans out as she takes his cock into her mouth. He groaned and began to lick faster. Tia bobs her head back and forth along his length. 'This is great.' he thought. 'You taste good as well.' she complimented him as she continues sucking.

They started to go faster and harder as their limits slowly approach them. 'Gonna cum!' they thought at the same time. With that, they both moan out, spraying their seeds and juices respectively to the other. Both tried to swallow the others as much as they could. 'You're certainly sweet.' he said in his thoughts. 'You too.' she replied.

Tio smiles as he said. "It's time for the main event." They sat up as Tio held his sister's legs opened. He climb onto tia as he lines his cock up to her pussy. "Brace yourself." She takes a deep breath as Tio starts to push inside her. She bit her lip as he pushed through her hymen. But it was more painful as she thought as she cried out in pain. "Sorry!" cried out Tio. Tia was tearing up as Tio went to her and kisses her softly. Tio stayed still as the pain slowly faded away. 'It'll be okay.' he told her softly as it goes down. She took a moment to catch her breath and nodded her head. Tia still has tears in her eyes, but she smiles to him, "Please keep going.." she said softly. "If you insist." spoke Tio slowly pulling back, then going back into her, moaning from her tightness.

Tia moaned at her first ever cock. She never thought it would be like this. Her first cock belonging to her brother. "Just how long have you've been thinking about this?" Tia ask him though moans. "A long time." he grunted. "R-really? How did this happen?" Tio looks at her with a confused look. "Like, how did you started to like me?" "When we began to hit puberty." "Oh." Tia said with a blush. "I did found you handsome Tio." He grinned before he began to go faster. "And I found you very beautiful Tia." he told him Tia blushed at hearing that. "Aw Tio." she said his name sweetly. "Tia." he said her name as he went to her and kiss her passionately, their tongues wrestling with each other. She held him close as he began to go faster.

She starts to grow warm from the feeling. 'Brother, I'm close.' 'Same here.' he replied. "Please cum inside me~" she smiled. 'You sure?' 'Hmm?' she wondered what he mean. 'You could get pregnant.' he groaned. 'I think having kids would be nice. Go right ahead.' she said reassuringly. Tio was stunned and couldn't stop as his dick twitched and began to fill her pussy. His seed went through her all the way to the womb. She let out a silent moan of content at feeling it fill her up. They both pant as the ordeal left them tired as Tio lays on top of his sister. "Amazing..." moaned Tia. "Y..Yeah...me too." he moans out looking back at Tia. The two share a kiss as the go and take a nap.

(3 months later.)

Tio smiled as he walked into the cavern where he and his sister resided in. He looked to see that she isn't here though. "Tia? Where are you?" called out. A door opened leading to the bathroom as Tia in her Latias form came out. It was visible of how swollen her belly had gotten. "Well it seems you were right about me being pregnant." Tia said with a giggle. "Told you." he chuckled. "Well at least I have a father who I know who can take care of it along with me." Tia said teasingly as she embraces her brother. He smiled and held her with extreme care. Tia shudders from his touch as she notices his face getting closer. Their lips pressed against each other. Both hummed in each others mouth as the enjoyed their love filled kiss.