I Found an Open Opening
Probably anyone who has studied the first chapter of Tractate Ketubot in the Talmud is familiar with the phrase “I found an open opening” (“פתח פתוח מצאתי”). For those interested in exploring this question from the perspective of Talmudic literature, I recommend my friend Josh Kulp’s article “‘Go Enjoy Your Acquisition': Virginity Claims in Rabbinic Literature Reexamined,” HUCA 77 (2006), pp. 33-64. Josh’s translation and commentary of the first chapter of Mishnah Ketubot can be found here (.doc).
On what basis, I thought, do we continue to assume that Marie remained a virgin until her wedding night? Was it possible that young women of her time knew how to convincingly fake it? A little more research led me to Ambroise Paré, whose 1573 treatise on “monsters and marvels” includes the description of popular techniques, known since the time of Galen, for creating false evidence of virginity by inserting a fish bladder filled with blood into the vagina, so that the sheets on the wedding bed would be stained with the necessary proof. Paré further argues that the very existence of the hymen in the female anatomy is at best questionable, and possibly simply a myth.
For additional discussion about virginity in a Jewish context see this article and the literature cited at the end.