Several characters exhibit surprise that the twins could have had a sexual life while being conjoined. However Chang and Eng Bunker, conjoined twins from Siam from whom we get the term 'Siamese twins', were not only married, they had 10 and 11 children respectively. They shared one home with a bed built for 4 until their wives (who were sisters) had a falling out, after which Chang and Eng split their time between their wives' houses.
In a magazine interview Emily Deschanel was asked what was her favorite episode. She said that she especially liked the ones where she got to go undercover, and cited this one as her favorite.
Dwight H. Little and Jason James Richter's third collaboration.