No sense in pointing blame at them for not playing it safe. If your sexual health and safety is a concern for you, guess who is responsible for that.
Yes, you are absolutely 100% right. And I don't blame them. We were all responsible for having that conversation, and we ALL failed at it. Including me.
I was swept away, I acknowledge that, and I made what could have been a bad decision. I've been tested since, and will repeat in 6 months to be sure, my doctor insists. The truth is I implicitly trusted him, as he did me, as she did me. And I am, still, very sure every test will come back clear. That doesn't make it ok though.
To answer your questions about terminology, it almost doesn't matter because from what she's said, it seems clear that she is basically telling you that she wants to be in control and managing your relationship with her husband and will not stand for you managing your own relationship with him. She only wants certain feelings to be allowed and not others. Which is, of course, insultingly ridiculous and nothing I would ever tolerate.
Which is about fear. As bookbug said, she was expressing fears not about what *I* would do, but about what *she* would do. And events not directly connected to me have broken through that and allowed us to start discuss her true fears instead of 'rules'. The fears that the rules were meant to contain are out in the open now and being discussed with some painful - but hopefully healing - honesty.
I was considering being willing to live under her 'rules' with a sunset clause, but new events have moved that out of the realm of possibility. I won't accept them any more, and he won't either. And she acknowledges why she had the fear, and understands why the rules were in place, but also why they wouldn't be effective.
We are now negotiating agreements with all of us having an equal voice. Which is where I had hoped we would get to, but was doubting was possible. And that doubt was feeding my own fear... which was getting circular! This feels much healthier.
PS. I love your R.A.H. quote. That is how I love.