My W's PA lasted 4.5 months, close to your H's 5. ow blackmailed my W, too, with the threat of outing her (and the threat of killing herself). My W gave ow a ring as a 'sort of' engagement ring, since same sex couples can't M in Illinois.
This just boggles my mind. How can anyone be engaged to person 2 while M to person 1? It just doesn't compute for me - my brain just stops.
For me, the 'engagement' is so far removed from reality that I pretty much discount it entirely, so it becomes a pretty small part of the whole recovery from the A project.
Also, I think the whole A was out of touch with reality, so nothing I've heard about her 'relationship' with ow has really stuck out for me - it's ALL bad.
That's my experience, which I offer tentatively. That's because I think if it had been an om instead of an ow, I might perceive the 'sort of engagement' as a bigger threat. Also, the ring was pretty cheap - if it had cost a more substantial sum, I might be more upset.
Still, if her ap had been an om, and if my W behaved consistently for R, with virtually no lapses, I think I'd come to the same position - she was out of her mind during the A, and nothing in it was real.
I hope that helps.