I'm sure different people have different opinions, but my definition of boundaries tends to be personal. You don't need to have a R conversation to set a boundary - you examine your own values and feelings of self-worth.
In my sitch there were some things that I decided I was willing to forgive and other things that went beyond the pale. I'm sure Puppy over in Infidelity would say that I was willing to forgive too much, and he's probably right. But when my W asked me to wait 6 months while she tried to make a R work with OM, I told her she'd crossed my ethical and moral boundaries and I wasn't willing to put up with it anymore. We've been on the road to D ever since, but I can feel better about myself.
It has always helped me to write things down. What I needed, what I expected, etc. Maybe that would help you clarify things for yourself?
