Look very carefully when the woman is leaning out of the window on the space ship and screaming. Above her, it is labeled "MST-3K"; this is referring to the classic B-movie making-fun-of TV series Mystery Science Theater 3000.
Alien: Come out of our movie, you're ruining everything.
(a toilet flushes and Wakko comes out and kissies the alien)Wakko: Thank you. (runs off)Alien: Aw, disgusting. He didn't even wash his hands.
Wakko: (whispering) I have to potty!
Yakko: What?
Wakko: (whispering loudly) I have to potty!
Yakko: What?
Wakko: I have to POTTY!!!
(Everyone in the theater goes "Sshhh!" to Wakko.)