The hymen isn’t a flap of tissue that covers the whole vaginal opening (except in a few rare cases of imperforate hymens.) It’s a ring of tissue around the vaginal opening, and isn’t so brittle that it’s torn once and then it’s gone. You can get a better idea of what it looks like here (medical illustrations, not photos, but probably NSFW). A very good overview of the hymen, bleeding during sex, effects of other activities like horseback riding, etc. is here (pdf), in very clear layperson’s terms.
http://menstruationresearch.org/2009/12/08/recognizing-the-vaginal-corona/
There has been varying research done, and the RFSU has put out a PDF explaining the actual anatomy of a woman, and how it really works. It works to dispel the many, many myths about the physical anatomy of human women. The “hymen” isn’t a membrane or cover or flap of skin that has to be “broken” at all.
Perhaps you were a bit more, uh, endowed than her previous partners?
She said by quite a bit.
From the first link:
Fascinating. You have to wonder if it contributed to the legend of the vagina dentata.
Although I doubt if it’s necessary. The idea would naturally have come up because of the similarity t the mouth. But this’d help.