My Alpha Brother is my Mate

Alpha Duncan

Derek was standing way too close to Mindy, his hand resting low on her back, fingers brushing the curve of her waist as he owned her. My wolf snapped. Before I could think, I shoved him hard enough to make him stumble back a step.

"Back off," I growled low.

Emma grabbed my arm right away, her nails digging in just enough to get my attention. She stepped between us, voice calm but sharp, the way only a future Luna can sound when she's trying to save face in a room full of powerful people.

"Duncan, what is wrong with you?" she hissed under her breath. "Everyone's staring. Your sister, your family drama-handle it in private. This is our engagement party. Not a battlefield."

The whole ballroom had gone quiet for a second. Heads turned. Alphas raised eyebrows. Ministers whispered behind champagne flutes. I could feel the weight of every gaze like a physical thing pressing on my skin.

I clenched my fists so tight my knuckles cracked. Took a slow breath. Forced my shoulders down. Then I pointed one finger right at Mindy's nose, close enough that she had to lean back a little.

"Just for now," I said through gritted teeth. "Only because I'm not about to let you ruin my engagement party in front of the entire pack and half the country's business elite."

Mindy's eyes flashed. She raised one perfectly shaped brow, then the other, mocking me with that little sarcastic wave she does when she knows she's winning.

"Oh yes, listen to your wise, perfect fiancée," she said, voice dripping with fake sweetness. "So mature. So in control." She turned to Derek, looping her arm through his. "Sorry about the little family scene, babe. Come on-let's dance. I need to move before I say something I'll regret."

She shot me one last look-pure fire-then tugged Derek toward the center of the dance floor like she was daring me to follow.

I watched them go. He was tall, broad, dressed in a tux that screamed old money and custom tailoring. Expensive watch. Confident posture. He didn't look like a gold-digger chasing her last name or my connections. That made it worse. He looked like he actually deserved her. And that thought burned hotter than anything else tonight.

I forced myself to turn away. Grabbed Emma's hand.

"Let's dance," I muttered.

She didn't argue. We moved to the center of the floor. The pianist played something slow and elegant, soft piano notes floating over the crowd. Emma pressed close, her hand on my shoulder, whispering, "You need to breathe. People are still watching."

"I know," I said. But my eyes kept drifting to Mindy and Derek. He had his arms around her waist now. She was laughing at something he said. Laughing. The sound cut through the music like a blade.

Then she pulled away from him. Walked straight to the pianist. Whispered in his ear. He nodded, smiled, and handed her the microphone.

The music faded. Heads turned again.

"Excuse me, everyone," Mindy said into the mic, her voice sweet but edged with something dangerous. She gave a small, charming laugh. "I'd like to sing a song. For my boyfriend. Is that okay? Just one little song?"

A ripple of amused applause. People thought it was cute. Sweet. Romantic.

I knew better.

She was furious. I could see it in the tight set of her jaw, the way her fingers gripped the mic too hard, the glitter in her eyes that wasn't happiness-it was rage. I'd raised her. I knew every tell. She was holding it together by a thread because of me. Because I'd dropped the engagement bomb without warning her. Without giving her even a heads-up.

My heart started pounding harder.

She began to sing.

Her voice filled the room-clear, warm, heartbreaking. The same voice I'd heard singing lullabies when she was little, humming in the kitchen while she made coffee, whispering goodnight through my bedroom door when I worked too late.

The song was one I loved. One she used to sing to me all the time lately-softly, almost like a secret. She never knew why it hit me so hard. It wasn't just the melody. The lyrics were everything I felt for her but could never say.

She closed her eyes as she sang.

"Said I was in love with you, but I lied to you...

This is more than the love I feel within me...

I told you I adored you, but I was mistaken...

Because love will never ever feel this strong again..."

Every word landed like a confession. She wasn't looking at Derek. Not once. Her body faced the crowd, but when her eyes opened at the end, they locked straight on mine.

My chest caved in. I couldn't breathe. Couldn't think. All I wanted was to cross the room, pull her into my arms, hold her so tight she'd never doubt how much she meant to me.

But she didn't give me the chance.

Jealousy flipped a switch in her. She spun around, grabbed Derek by the collar, and kissed him-deep, desperate, right there in front of everyone. Her hands in his hair. His arms wrapped around her like he'd been waiting for this moment.

It felt like someone drove a knife straight through my ribs. My heart squeezed so hard I thought it might stop. Tears shimmered in her eyes even as she kissed him. I saw them spill over, slide down her cheeks.

I lost it.

I stormed across the floor. Shoved Derek back so hard he almost fell. Then I swung a fist, connecting with his jaw. Blood sprayed. His nose crunched. He staggered, hand flying to his face.

"Get the fuck out of my house!" I roared.

He wiped blood from his lip, eyes wide but not scared-more stunned. "Alpha Duncan... I really like her. I haven't done anything wrong. She's my girlfriend. She said yes when I asked if she'd consider mating with me someday. I'd propose right now if you'd let me-"

The more he talked, the redder everything got.

"Get. The fuck. Out," I snarled, stepping closer. "And don't ever come near my sister again. That's not a request."

He looked at Mindy. She was shaking, tears streaming. He swallowed hard, nodded once, then turned and walked out-fast-blood staining his white shirt.

Mindy whirled on me.

"How could you?!" she screamed. "He's my boyfriend! I was going to mate with him-whether you like it or not! You don't get to decide who I love!"

Something snapped.

My hand moved before my brain caught up. The slap cracked across her cheek-sharp, loud. The sound echoed.

She froze. Hand flying to her face. Eyes huge with shock and hurt.

"What... are you doing?" she whispered, voice breaking.

Tears poured down her cheeks now. Fast. Silent.

I stared at my own hand as it belonged to someone else. My stomach twisted. I'd never hit her. Never. Not once in all the years I'd raised her.

But the thought of her mated to him-to anyone-had ripped something loose inside me.

I couldn't speak. Couldn't apologize. Not yet.

Instead, I grabbed her wrist-gentler this time-and pulled her through the crowd. People parted like water. Emma called my name once, but I didn't stop. Didn't look back.

We climbed the stairs in silence. Mindy didn't fight. Didn't pull away. Just followed, head down, tears dripping onto the marble.

I kicked open her bedroom door. Slammed it shut behind us. Pushed her gently but firmly against the wall.

"You are never mating with him," I said, voice rough. "Never. I'll find someone worthy. Someone who-"

She cut me off.

Her hands fisted in my collar. She yanked me down and crashed her lips against mine.

Hard. Hungry. Desperate.

I froze for half a second-then the dam broke.

My hand slid to the back of her neck, fingers tangling in her hair, pulling her closer. I kissed her back like I'd been starving for years. Tongue sweeping in, tasting her, claiming her. She moaned into my mouth-soft, needy-and it undid me completely.

When oxygen finally forced us apart, I stumbled back, chest heaving.

"What the fuck have we done?" I rasped, dragging both hands through my hair. "Mindy... we can't-"

"I'm so fucking in love with you!" she shouted, tears still falling. "We're mates, Duncan! Don't lie to me anymore! Don't lie to yourself! I'm not letting that bitch take you away from me. Not ever again."

She stepped forward, hands shaking as she reached for me.

And in that moment, with her lips swollen from our kiss, eyes blazing with love and pain and fury...

I didn't push her away.

I didn't run.

I just stood there-heart hammering, wolf howling-and realized the wave had finally crashed.

There was no swimming back to shore now.