I've discussed this topic before, especially because I'm in the minor leagues I get to observe the more severe variants almost from the perspective of someone that hasn't been betrayed at all.
For each person, the betrayal they have to deal with is kind of the worst one. You can't sit there and excuse it as "well at least it wasn't...." because it lends itself to minimization on the part of the WS.
All that said I have a number of factors to consider that I believe on each continuum make it worse. Each ranging from "none" to some further end.
Required aspects of a betrayal:
Emotional - Top end of this is something like them having exchanged "I love you" and meant it (at least in the moment).
Physical - Top end is sex acts denied to BS and transmitting STD to BS.
Duration - top end is they were never faithful.
Priority / Level of deceit - top end is skipping a major life event in the family such as funeral/graduation/etc. to be with AP instead.
Optional bonus menu:
Double betrayal - involving someone else you trusted, top end is sibling/parent/child/best friend.
Financial - top end is taking on a huge amount of secret debt to fuel the A.
Purity - BS has no other sexual partners.
Location - marital bed and landmarks of shared meaning.
I'm sure there are other ways to make it worse.
What I don't know is how much of any one of these things I would be able to R through. I wouldn't expect my current R if you asked me before my wife's A. Ask me now and I say DDay 2 of any kind equals divorce. Ask me again on DDay 2 if you want the real answer. I don't really *know* what the answer is.
[This message edited by This0is0Fine at 10:04 PM, Tuesday, November 11th]