Flirting with My Boyfriend’s Younger Brother – We Started Secret Late Night Chat

Read previous part: I Cheated on My Boyfriend with His Hot Younger Brother – The Secret Attraction Begins

The next three days felt like sweet torture. Every time I visited Arjun’s house, Karan was there - acting normal in front of everyone, but stealing glances at me that made my stomach flip. I couldn’t stop thinking about that accidental like on my bikini photo. He had been stalking me. Wanting me. And the more I thought about it, the wetter I became.
On Friday evening, Arjun had to go out for a sudden office dinner with his father. He dropped me at their house and said he’d be back by 10. Aunty had gone to a relative’s place for the weekend. That left just me and Karan alone in that big luxurious house.
I was wearing a soft pink crop top that showed a teasing strip of my waist and tight grey yoga pants that hugged my round ass perfectly. No bra. My nipples were already semi-hard from anticipation.
Karan was in the living room, playing PS5 in a black t-shirt and grey sweatpants. The moment I walked in, his eyes locked on me. Those sweatpants… God. They were thin and revealing. I could clearly see the heavy outline of his cock resting against his thigh. It looked big even when soft. Much bigger than Arjun’s.
I pretended not to notice at first and sat on the couch opposite him, curling my legs under me.
“So… where’s your girlfriend tonight?” I asked casually, keeping my tone light and playful. “You never bring her home. Arjun told me you’re seeing someone from college.”
Karan paused the game and looked at me with a small smirk. He scratched the back of his neck, looking slightly embarrassed.
“I don’t have a girlfriend, Riya,” he said, his deep voice sounding honest.
I raised an eyebrow. “Really? Come on, a hot guy like you? All those gym selfies and bike rides… girls must be throwing themselves at you.”
He chuckled and shook his head. “There was this girl last year, but it didn’t work out. Since then… nobody serious.” His eyes moved slowly over my body, lingering on my bare waist and the way my nipples poked against the thin top. “I guess I’ve been distracted by other things.”
My heart beat faster. The tension in the room thickened instantly.
I shifted closer on the couch, now sitting only a few feet away from him. “Distracted by what?” I asked softly, biting my lower lip.
Karan’s gaze dropped to my lips, then lower to my breasts. He swallowed hard. “Just… life.”
We started talking properly for the first time. Real talk. He told me how pressured he felt being the younger brother - always compared to Arjun. How he loved bikes and gym but his dad wanted him to join the family business seriously. I opened up a little too - how I sometimes felt lonely even in a relationship, how Arjun was always busy with work.
The conversation flowed easily, but the air was charged with something much hotter.
After some time, I “accidentally” dropped my phone between the couch cushions and bent over to pick it up, pushing my ass towards him. When I sat back, I noticed his cock had grown. The bulge in those grey sweatpants was now thick and obvious, straining against the fabric. It looked heavy. Long. My mouth watered.
I decided to be bold but playful.
I giggled softly and pointed with my eyes. “You know… your girlfriend - or future wife - is going to be one very lucky girl.”
Karan looked confused for a second. “Why suddenly?”
I smirked and let my eyes drop shamelessly to his massive bulge. “Because of that. That thing looks dangerous. Girls talk, you know. If it’s as big as it looks in those sweatpants… she’s going to have a hard time walking the next day.”
Karan’s eyes widened in shock, then he burst out laughing, but his ears turned red. He adjusted himself, which only made the bulge more prominent.
“Riya! What the hell?” he said, grinning but clearly turned on. “You can’t just say that to your boyfriend’s brother.”
I shrugged innocently, enjoying the power. “What? I’m just being honest. It’s very… noticeable. And impressive. Arjun never gets that hard that fast.” I covered my mouth dramatically. “Oops. Did I say that out loud?”
Karan stared at me, his breathing heavier now. The playful banter had crossed a line, and we both knew it.
“You’re dangerous, you know that?” he said, his voice lower and huskier. “If Arjun heard you talking about my dick like this…”
“But he’s not here,” I whispered, scooting even closer until our thighs were almost touching. “And I’m just teasing. Unless… you don’t like me noticing how big you are?”
He didn’t answer with words. Instead, his eyes darkened with pure lust. I could see his cock twitching visibly in his sweatpants now, growing even thicker. The head was clearly outlined. My pussy clenched hard. I was soaking through my panties.
We kept talking, but now it was laced with heavy flirting. I teased him more - asking if he liked curvy girls, if he preferred girls who moan loud, if he lasts long. He answered every question while staring at my body like he wanted to devour me. The sexual tension was so thick it felt hard to breathe.
At one point, I leaned forward to pick up the remote, letting my breast brush against his arm. He didn’t move away. His hand lightly touched my bare waist for a second - electric.
By 11 PM, Arjun texted that he’d be late and would pick me up tomorrow morning instead. Perfect excuse.
I told Karan I should probably head to the guest room, but before I left, I smiled at him sweetly.
“By the way… if you ever feel like stalking my Instagram again, at least don’t unlike so fast next time,” I said with a naughty wink.
His face flushed. “You saw that?”
“I did. And I liked it.”
I went to the guest bedroom but couldn’t sleep. My body was on fire. I kept replaying how huge his bulge looked, how his voice got rough when he was turned on, how dangerously close we had come to crossing the line.
At 1:17 AM, my phone buzzed.
Karan: Hey… you still awake?
My heart jumped. I smiled in the dark and replied immediately.
Me: Yeah. Can’t sleep. Someone made me too restless 😌
Karan: Who? The guy with the “impressive” sweatpants? 😂
Me: Exactly. That bulge is dangerous bro. Your future wife needs to start training now.
Karan: Riya stoppp 😂 You’re killing me. Arjun’s girl and you’re talking like this?
Me: Arjun is sleeping at his friend’s place. It’s just us in this big house… and I’m really horny tonight.
I sent it before I could overthink. The message was risky. Very risky.
He replied after a minute.
Karan: Fuck. You can’t say things like that to me.
Me: Why not? You were the one stalking my bikini pics. I know you want to see more.
The chat continued late into the night. We started innocent but quickly turned filthy. He confessed that he had been attracted to me since the day Arjun brought me home. That he jerked off thinking about me many times. I told him how unsatisfied I was with Arjun, how I needed a man who could actually fuck me properly.
By 3:30 AM we were sending risky messages - me describing how wet I was, him telling me how hard his cock was right now in his room. We didn’t send nudes yet, but the tension was explosive.
I finally typed:
Me: Karan… if we keep talking like this, something is going to happen. And once it does, there’s no going back.
Karan: I know. But I don’t think I can stop anymore.
I fell asleep with a smile, pussy throbbing, already imagining what his thick cock would feel like stretching me open while my boyfriend was completely clueless.
This was no longer just flirting.
I was falling for my boyfriend’s younger brother… and I wanted him to ruin me.