- Right from the start, it's obvious Billy is taking advantage of Ernie's low self-esteem. Ernie, with his many urinary problems, clearly has very few friends and will do anything to win Billy over, even something as embarrassing as calling his teacher. Ernie obliges without argument.
- Billy prompts Ernie to ask a series of unseemly questions regarding Ms. Vaughn's "status" (Does she have a boyfriend, Does she like anyone in class more than a friend, etc.). Ernie does so flawlessly, in my opinion.
- Billy then tries to push the limits of what is appropriate by telling Ernie to ask her if she'd ever consider dating anyone from class. When Ernie objects, Billy screams, "Just DO IT!" Again, Ernie does as he is instructed.
- As she starts to answer, Billy then gets on another phone to listen for himself. When it becomes clear that Ms. Vaughn has mistaken Ernie's questions as an indication that he (not Billy) has a crush on her, Ernie gets right to the point and asks her about Billy. When her response is not the desired one, Billy chimes in using a high-pitched voice that is supposed to imitate Ernie (but sounds nothing like him) and says something impulsive. His comment raises suspicion and he is forced to abort the mission and hang up abruptly. He then berates poor Ernie, yelling, "You BLEW IT!"
If you want to judge for yourself, the scene is HERE.
Edited to add: I guess Billy does make up for it somewhat with the fake pants-wetting bit.