Yall both were walking into the sewers finding the lair at the right and so for nobody noticed that Donnie left, they all thought he was still in his lab doing what he does best. As usual Mikey was yelling at the video games he was winning on, Raph ignoring him shoving his face in a brutal but awesome comic book and Leo in the dojo meditating like always.
Donnie looked down at the dozed off girl in his arms and tightened his grip on his sack he had and quietly walked inside the lair trying not to get caught. He opened his lab door just enough for him to get in there until he got hit in the back of the head with a ...
Donnie: ughh Mikey what'd you hit me with?
Mikey: I don't know I couldn't find my water balloon so I just grabbed whatever that blue--brown moldy, hairy, soggy thing was from under the couch
Donnie was far from grossed out and he knew way better than to scream at Mikey right now from trying to keep the baby asleep. He rushed into the lab and placed the little girl in a small bowl and ran to the science showers
( I don't know what those things are called I just see them at school)
10 minutes of Mr.Nerd scrubbing that crap off of him, he finally got it all off with some bleach, a detergent , a screw driver, and a chain saw and BUBBLES .
He dried himself off and went to go check on you, when he got there he saw everyone even Master Splinter crowded around his work space.
Mikey: Dude when did you get a pet?
Donnie: She's not a pet Mikey, I found her almost getting oozed by Kraang
Leo: and so you saved her
Donnie: absolutely
Sensei: Donnetelo does she have a family
Donnie: no Sensei but what about she be in our family
Sensei: She may live under this roof but you have to treat her like she is your own
Donnie: Yes Sensei, thank you
Raph: so whats the little nerds name
Mikey: what about Pizza
Raph,Leo,Donnie:NO!!!!!!
Donnie: how about (y/n)