Sinful Obsession: My Billionaire Stepbrother

Different worlds

~Isabel~

"Which university did you graduate from?" I asked as we drove.

I kept my voice casual and looked at his profile. He had a sharp jawline with a hint of morning stubble.

He didn't answer right away.

Instead, a lazy smirk tugged at the corner of his mouth. He looked at me with a flash of genuine amusement, his whiskey-colored eyes twinkling with an unexpected mischief that made my stomach flip.

"What’s funny?" I asked, frowning. I ran the question through my head, trying to see if I missed some joke.

"Is it a secret? Did you go to school in a basement?"

"Nothing." He tapped his fingers on the steering wheel, his expensive watch catching the morning sun.

"I’m just thinking maybe you’re finally interested in me. Did the flirty waitress give you a wake-up call?"

"Ha!" I gave out a dry laugh and leaned back against the headrest.

"How could I be interested in you? It’s not even like that. You know you’re my brother."

"Step-brother," he corrected instantly.

The word came out sharp, like a line drawn in the sand. He didn't say it like he wanted to be family; he said it to make sure I knew we weren't.

"Yeah, whatever. We’re family now, so of course I want to know something about you. It’s called being polite, William. You should try it sometime."

The amusement vanished from his face just as fast as it appeared.

The air in the car turned back tensed again, and the lighthearted moment died instantly under that familiar chill.

"Don’t get your hopes up, Isabel. I still don't like you, and I still don't want you here." His voice was clipped and clinical.

It felt like a slap.

"I’m just trying to be a little kind and human because I left you the other day and you got caught in the rain, This isn't a bonding exercise. It’s my obligation.

"I am being a responsible person here its the right thing to do that's all..."

I felt the sting of his words deep in my chest, so painful and stabbing that made it hard to swallow my spittle.

I slowly pulled my hands away from the side of the seat where they had been resting comfortably.

I folded them tightly in front of me, my face now flushing a hot, painful red.

I felt small. I felt like the interloper—the girl from Brooklyn, New York who didn't belong in his world or his car.

He looked down at my hands, watching my sudden, defensive movements to gauge my reaction.

He saw the way I pulled away and curled into myself, but he said nothing. He just turned his attention back to the road, his face shifting back into an unreadable mask.

I turned my head toward the window, blinking repeatedly to stop embarrassing tears from prickling my eyes.

I wasn't going to cry in front of him. I felt so incredibly naive. For a second, back at the cafe, I actually thought the walls were coming down.

But I was wrong.

We were worlds apart in every way. Money, looks, friends, and our lives—everything was a barrier.

Someone like William was born into this world of effortless wealth and power.

And his looks... even if he wasn't a billionaire, I’d never dream of being near someone as perfectly handsome as he was.

I was just an outsider trying to find a place in a house that already had a king.

We pulled through the large campus gates, and the atmosphere shifted instantly.

The university was bustling with morning energy, a sharp contrast to the suffocating tension inside the SUV.

The school was beautiful, just like I had imagined.

Ancient trees lined the stone walkways, and vibrant flowers burst from every corner. At the center of the main entrance stood a massive bronze statue of scholars, surrounded by students caught up in college life.

Some were chatting excitedly in groups with coffee cups in hand, making new friends and catching up, while others rushed toward the stone buildings for early lectures.

Scattered around the lawns were iron benches where students sat reading, relaxing, or soaking in the sun.

Campus life was supposed to be fun. It was supposed to be my fresh start. I took a deep breath, trying to push the embarrassment into a dark corner of my mind, I fully intended to enjoy this.

But as the black SUV rolled on slowly through the crowded square, I realized we were the center of attention. Students stopped mid-sentence to gape at the car. It was too sleek, too expensive, and way too loud for a college campus.

"Oh, my bad," I whispered, panic rising in my throat. "I shouldn't have accepted the ride. Now I'm going to get way too much attention."

William slowed the car to a crawl near the law building.

"What’s wrong with you getting attention? Don't pretend like you don't like it. You wore those jeans for a reason, didn't you?"

I looked at him in total shock. This!...

My mouth opened to retort, to tell him off, to scream that I dressed for myself and not for his twisted ego, but I couldn't find the words. My brain felt short-circuited.

What did he take me for? Some shallow girl looking for a spotlight?

Hot, blinding anger finally bubbled over.

I didn't wait for him to properly clear the car, I hit the handle and stepped out of the it before he’d even fully stopped.

I grabbed my bag and slammed the door with a thunderous thud that made a few nearby students jump. I wanted to leave him there, disappear into the crowd, and never look back.

But to my absolute surprise, William did something I never thought he’d do...