I shoved my older sister Lena against the bedroom door the second our parents left for the weekend. Her tits heaved under that thin tank top, nipples already hard. "Been thinking about your cunt all week," I growled, yanking her shorts down. No panties. Her shaved pussy glistened, lips puffy and pink. Lena moaned when I dropped to my knees right there.
I spread her thighs and buried my face in her. My tongue dragged straight up her slit, tasting how wet she already was. "Fuck yes, little sis," she hissed, grabbing my hair. I zeroed in on her clit, sucking it hard between my lips like I knew she loved. It throbbed against my tongue, fat and sensitive. I sucked it in pulses, then flicked it fast while two fingers slid into her tight hole.
Lena bucked against my mouth. "Suck it harder, you dirty bitch. Make your big sister come on your face." I obliged, sealing my lips around that swollen clit and pulling with steady suction. Wet sounds filled the room. Her juices coated my chin. I curled my fingers inside her, hitting that spot that always made her shake.
She came fast, thighs clamping my head, clit pulsing under my tongue as she flooded my mouth. "Don't stop," she panted. I kept sucking through the aftershocks, gentler now, until she pulled me up and kissed me deep, tasting herself on my lips.
We moved to the bed. Lena stripped me and pushed me onto my back. "My turn to suck that pretty clit." She spread my legs wide and dove in. Her tongue was rough and eager, circling my clit before she sucked it between her teeth. The pressure made my hips jerk. She slipped two fingers into me and pumped while she worked my clit with strong, wet sucks.
I grabbed the headboard. "God, Lena, your mouth feels so fucking good on my cunt." She moaned into me, the vibration shooting straight through my clit. She alternated sucking and licking, then flattened her tongue and dragged it side to side over the sensitive bud. I felt the orgasm building fast.
When I came, it was loud and messy. My pussy clenched around her fingers while she kept sucking my clit through every wave. She didn't let up until I was trembling and oversensitive. Then she crawled up, pressed her soaked cunt against mine, and we ground together, clits rubbing slick and hot.
We spent the whole weekend like that. Morning clit sucking in the shower, afternoon sessions on the couch where she'd sit on my face and I'd tongue her swollen nub until she squirted. Nighttime slow, dirty sixty-nine where we sucked each other's clits in perfect rhythm, fingers buried deep, moaning into each other's pussies.
By Sunday night we were both raw and satisfied, lying tangled with the sheets soaked. Lena kissed my forehead. "Same time next weekend, little sis." I smiled and slid my hand between her legs one more time, giving her clit a final soft suck with my fingers.

She moaned low. Our secret stayed locked tight, just the way we liked it.