fwiw, I too -- on these very forums -- was being warned that I was coming across as "holier-than-thou" when I thought all I was doing was standing up for fidelity in my marriage.
I fought those people at first, but eventually -- since several people or different DBing philosophies all seemed to be pointing it out -- I figured it:
a) must really be something I need to work on; and
b) was probably coming across -- big-time -- to my wife.
So I made a conscious effort.
I found that when I focused just on fidelity, I got very smug: "Hey, I've been faithful, but SHE HASN'T!" But when I thought of it from the Biblical perspective of "all have sinned, and fallen short of the glory of God" . . . or to look at it secularly, "we all have stuff we're knuckleheads at!" . . . it helped.
In other words, there were areas of my life that were nearly as screwed up as the fidelity part of my wife's life. And so I remembered that, and it humbled me.
