Present- Derek has a moment
Stiles tried to muffle his cry of pleasure into his pillow as Derek pressed in. He let out a strained whimper and peeked out of the corner of his eye at his son, who is sleeping, not even ten feet away, in his crib. A choked sound passed through his throat again when Derek pressed in and rubbed against his prostate. He let out a loud keen and Derek stilled.
"Quiet." Stiles shook his head no, unable to say it. Derek pulled out, pressed back in, and smirked when Stiles' breath hitched. He repeated his actions and was rewarded with the same sound. "I'm not sure what I like more. Your uncontrollable babble or you like this, trying so hard to be quiet while your Dad sleeps down the hall and our son sleeping in the room." Stiles tried to move off of Derek's dick, but was pulled back by clawed hands on his hips. "Are you trying to get away?" Derek asked softly with a chuckle.
"D-Derek." Stiles' hands clawed at his blankets and he clenched his eyes shut. "We…we…" He swallowed thickly. "He's…we'll…" He couldn't get his sentence out.
"He won't wake up," He pulled Stiles harshly back onto his cock, making the boy yelp. "as long as you're quiet."
"Mmm." Stiles pressed his face back into the pillow to keep himself as quiet as he could manage. He wanted to take another glance at Tyler to make sure the little boy was still sleeping but he was too embarrassed to open his eyes. He was having sex while his child was in the room. Sleeping or not, it was still embarrassing and unnecessary. "Derek, please." He panted out.
"Just take it. Don't talk." A low growl escaped Derek's throat and he buried his face into Stiles neck as he moved his hips in a torturous rhythm. Stiles gnawed at his pillow to keep the sounds from passing his throat. "That's it." Derek made sure he was hitting Stiles prostate. "Gonna fuck you full of me. Give me another pup. Tyler a brother or sister."
Stiles shook his head no. "B-birth control."
Derek growled. "Won't stop me from trying." His hands tightened on Stiles him almost to the point of pain. "Almost lost him." It took Stiles a moment to realize he was talking about Tyler. "Can't lose him, or lose you."
He felt sharp teeth against his throat. "Don't." Stiles gasped desperately. Derek growled but the teeth never went beyond a gentle nip.
"One day." Derek gasped and shuddered as he spilled himself inside of Stiles.
"Not today." Was Stiles' weak answer.