The air in the guest room was thick with heat and tension. After the tearful confession and Derek's fierce reassurance, Stiles couldn't hold herself back anymore. She wanted him-wanted him inside her, wanted to celebrate that she was his mama now more than ever.

She lay back on the bed, nightgown slipping off her shoulders, breasts spilling free, nipples already hard. Her eyes glistened as she whispered, "Derek... fuck me. Celebrate me.

Celebrate Us."

He growled low in his throat, hands pulling her gown down to her waist. "My girl," he muttered against her lips. "My mama. Carrying my baby."

And then he was on her-kissing her hungrily, grinding his hard cock against her thighs until she spread them open, needy and dripping.

"Please," she whined, arching her back. "Put it in me. I want you raw. Want you to fill me up more."

"Fuck," he hissed, lining up and sliding inside in one hard thrust. Her moan ripped through the room, desperate and slutty, as her nails dug into his back.

Every thrust was punishing, deep, filthy-like he wanted to brand her from the inside out.

Stiles's moans grew louder, wetter, filthier. "Yes, Derek! Yes, daddy-fuck me harder! Make your mama squirt all over your cock!"

Derek slammed into her harder, grunting in her ear, "You're mine, Stiles. My slut. My mama. Carrying my baby."

Neither of them noticed the door crack open.

Sara.

She had woken up thirsty, planning to grab a glass of water, when she heard the unmistakable sound of moans and the rhythmic thump of flesh against flesh.

Following it, she froze in the doorway, stunned into silence.

Her husband. Inside their nanny. Moaning filth in her ear while their son slept in the crib across the hall.

Her voice trembled with rage. "Derek— stop this right now!"

But they didn't.

Stiles, flushed and teary-eyed with pleasure, locked eyes with Sara. A wicked smile curved her lips as she clung tighter to Derek's shoulders. "Don't stop, Derek. Fuck me harder. Let her watch how your mama takes you."

Derek's eyes burned as he glanced at Sara-then back down at Stiles. He shoved in deep, groaning, "She's pregnant with my baby, Sara. She takes care of Eli better than anyone. She takes my cock better than anyone. Look at her-squirting all over me for it."

Stiles's body shuddered, and with a broken scream, she squirted across his cock and thighs, soaking the sheets. Her juices splashed, loud and obscene, while Sara gasped in horror.

"Derek!" she cried, voice shrill. "How could you-"

"Because she's mine!" he snarled, pounding Stiles harder, ignoring his wife completely.

"She's my mama. The only woman who makes me feel alive."

Stiles's head fell back, hair sticking to her sweaty face, as she sobbed in pleasure.

"More, Derek, please-don't stop-fill your mama again!"

He slammed deep, grinding, holding her down as she writhed. "Take it, slut. Take all of me.

You and our babies. This is where I belong."

Sara's furious scream was drowned out by the sound of Stiles's desperate cries, the wet slap of skin, the gush of another squirt.

Because in that moment, nothing else mattered to Derek and Stiles but each other-and the filthy, forbidden ecstasy that bound them tighter than any vow ever could.