A/N: this one's actually teen, or maybe even k, except I heavily imply shenanigans that take place right after the end of the drabble ~ there will be smut in later efforts, just thought I'd take the humorous route for this one.
"Ew. How can one small infant make such a big dirty mess?" Gajeel asked through his fingers clapped over his mouth, doing his best not to gag.
"Pfft." Levy levelled a glare on the iron dragon slayer. "He's your son, so there's that."
"Har de har har, Shrimp. I meant, he's only eating milk. How can he turn that into such …"
"Simple biology, taking nutrients out and discarding everything else." Levy didn't even try to hide her smirk. "Can't even say 'poop' Gajeel?"
Shaking her head, Levy bent to wipe clean her child. With efficient movements she slid a fresh nappy underneath, took the used one and secured it into a ball. "Go ahead and take this out to the trash." Levy held out the malodorous object to her husband. "Remember, the next change is all yours."
A scowl on his face; lips compressed and cheeks bulging, Gajeel took possession. Holding it like a ticking time-bomb, he hurried through the house and chucked it into the trash can.
Inside the nursery Levy was tucking the blanket around their child. "Ryu is clean and full. He should sleep for at least half the night."
"That's almost long enough, ghee hihi." Gajeel wrapped an arm around his petite wife, leaning over to whisper in her ear. "Time for our bath. After having that conversation about the content of diapers, I wanna get us all nice and clean. Then we can start our own dirty talk."