"Shall we tell him?"

"Shall we tell him?" it suddenly came from the still giggling 'Monica'.
"Tell me what? Wait, what is up with your voice? Why do you sound like a man?" Greg suddenly realizes.

"Greg, let me introduce you to my father, Walter! He looks like this due to his latest invention." Tim just speaks up before things get even weirder.
"Hi Greg! Tiny dick you got there!" Walter just continues giggling.

"DAD! You can talk! Look at yourself, you got no dick to talk about at the moment!" Tim rebuffed his father's attempt at insulting his roommate.