Hotel room keys? (I don't know. What is this, a trick question?)
No, seriously, I don't know a lot about unfaithful women. I've only had one woman in my entire life be unfaithful to me. Meh, I didn't dwell on it, the "relationship" was no deal-breaker anyway, so I just moved on to the next one. (Back then, there was always a next one.)
As in sexually faithful? I would say it is about how willing we are to risk the security that naturally comes to us through relationships, family, and being an accepted member of a larger community for something else - be it another relationship, family, or just the kind of strokes that can affirm us as people that don't necessarily come to us in playing supportive roles in a family or a community or in our work. We may be looking for something we would like but don't have and we are just very susceptible to attention paid to us.
Gee, what a coincidence: those are not only the exact two things it takes to file countless (and frivolous, I hasten to add) restraining orders, but they're also the exact two things it takes to overcome those same restraining orders! We were MEANT to be together, Sweetie-Pie!
~ 
Jane S 