“Darryl, have you seen your sister? We’re about ready to go grab lunch.”
“No idea, Mom. I did tell her she could use my computer for a bit, I’m sure she’ll be fine here until we get back. After all, she can start unpacking my stuff or something while we’re out anyway.”
“Yeah, makes sense. Alright guys, let’s go eat before we finish unloading then!”
As they all left to take a break from moving Darryl in, they completely forgot that his roommate was home. Not just home, but currently balls-deep in Darryl’s sister.
They’d figure it out soon enough though when they got back and found their cum-covered little girl exhausted on the couch and dripping.