i was in a marriage with a person like that-- he was mostly (but not always) very smooth and "easygoing" with strangers and coworkers, but would yell at me for bothering him if i had a cold and was coughing...etc....
many folks much smarter than i am in these forums seem to know right off to run forrest run when this goes on. i blamed myself, though, felt bad for him (there must be something wrong or something i could do, i kept thinking) and kept trying to "adjust" so he would be happier. i am still trying to get over the whole mess.
my ex is also deeply passive aggressive, a terrible way to live. and the weird thing is that working hard to process stuff and being kind/civil with people is very important to me. i agree with moraima:
If I wanted to fly off the handle at my s/o I would know it was time to get out of the relationship for both of our sakes.
well said.