Joan may be living in the here and now, but she still retains some 15th-century sensibilities about some things, like modest dress.
And no, I wasn't actually planning on Bethany dressing up as Alanis. Especially when Monica Lewinsky (with her notorious blue dress) is a more intriguing subject.
TRANSCRIPTION COURTESY OF JOSEPH HOUK - [Matt & Beth's new house – pretty spiffy! – with PW's truck
in the driveway] (JA) "So this is where Matt and Bethany
live now!" (CW) "Yep! And I didn't even help them get it!"
(PW, in "Beavis with a pornstache" costume) "Nice 'Xena'
costume, Joan! That one's a real good fit for you!" (JA, as
Xena the Warrior Princess) "I don't know… I'm a little
uncomfortable in this 'fit'!" (CW, as everyone's favorite
Tomb Raider, Lara Croft – from the original game series)
"I hope Bethany didn't have the same idea. She never did
let me know what she decided on…" [DING DONG] (BG,
opening the door in a dark wig and a little blue dress
with… uhm… a stain?) "Come on in! You're just in time!
You're lucky, Philip. I couldn't convince Matt to be Bill
Clinton." (CW, who suddenly realizes what BG dressed up
as…) "PLEASE tell me that's NOT Matt's… uhhh…" (BG,
as Monica Lewinsky) "Chill out. It's glue." (PW) "Hehheh!"