My h also has shown tremendous PA behaviors throughout his MLC. Hard as it is, I found not reacting (verbally or by body language) diminished the behaviors drastically. As Job says, this is learned behavior and I think they try to recreate a dynamic that, though dysfunctional, feels good because it is familiar to them from earlier days. Sadly, I do think it was a sort of "method" by which they learned to communicate in childhood.
When the PA is in your face, like when he makes snide comments, I would calmly but directly look him in the eye and ask: "what do you mean by that?" Then I would not say a word; just listen. You may be surprised by his reaction. When confronted many of them back peddle and stammer for words.
In general, I have found that I have had to teach my h that PA behaviors do not get him the reaction he wants. If you can get him to answer "what he means by his comments," then validate and say "thanks for explaining" even if you don't agree with what he says.
Like a child: try to ignore the bad, elicit the good and then praise.
Me 41, H 47, M 15 yrs, S11, S13 BD 1: 11/4/14 we work on it; really I pretzel myself BD 2: 3/31/15 H goes down to "dorm room" 8/15: H back to MBR 10/15: H back in dorm room 1/18: H files, now divorced
