She had been teasing herself with the idea for months, ever since the big mutt next door started pushing his nose between her thighs every time she wore shorts. At twenty-four, Lena was no virgin, but nothing had ever prepared her for the way her cunt clenched when she finally decided to let it happen. She locked the door, stripped naked on the living room rug, and whistled for him. The dog came bounding in, already half-hard, his red tip peeking from the sheath. Lena dropped to her hands and knees, ass up, and spread her knees wide. "Come on, boy. Fuck me with that dog cock."
He mounted without hesitation, front paws clamping her waist. The first hot poke missed, sliding along her ass crack. She reached back, grabbed the furry sheath, and aimed the slick, pointed tip at her dripping pussy. One thrust and he was in, deeper than any man had gone on the first stroke. Lena gasped, the heat shocking her. It was thinner at first but thickened fast, the tip jabbing straight against her cervix while the rest of the shaft swelled and pulsed.
"Fuck, yes, pound me," she hissed, pushing back. The dog hammered her with short, brutal strokes, his balls slapping her clit. Every slam sent wet sounds echoing through the room. Her juices ran down her thighs. She could feel him growing even thicker inside her, the knot starting to form at the base. It popped in and out a few times, stretching her entrance, then swelled fully and locked tight behind her pubic bone.
Lena moaned like a whore. The knot throbbed, stretching her open while the dog kept jerking, pumping hot, thin cum straight into her womb. She came hard, cunt clenching around the swelling bulge, legs shaking. The dog growled and stayed mounted, hips still twitching, filling her until cum leaked out around the knot and ran down her legs in sticky streams. She stayed on all fours, rocking gently, savoring the full, stretched feeling.
When the knot finally shrank enough to slip free, a gush of dog cum poured out of her.
Lena rolled onto her back, spread her legs, and fingered her sloppy hole while the dog licked her clean. She came again with his tongue lapping at her clit and the taste of his cum still on her fingers. By the time she stood up, her thighs were trembling and her pussy felt used in the best way.
She let him mount her twice more that afternoon, once on her back with her knees to her chest so he could drive even deeper, and once bent over the arm of the couch. Each time the knot tied her, each time he pumped another load inside. By evening her cunt was puffy, red, and leaking. She walked around the house naked, feeling his cum slide down her inner thighs, already planning the next time she would get fucked by that dog cock again.
