IMO, the Drama Triangle explains this. (Search the web or see karpmandramatriangle.com - citation OKed by mods.) Taking on the Victim role and not letting it go is the best description of pain shopping that I can think of.
In a DT, the Victim focuses his (or her) mind on feeling angry or scared or sad. When that stops working, a Victim often looks for other reasons to feel bad - that is, a Victim shops for pain.
The purpose of a DT seems to be to avoid confronting and feeling real emotions. The only way out of it that I know is from my own experience and from my own therapy.
1) I notice that I am feeling bad and seem to keep my mind spinning on feeling bad.
2) I ask and answer the question, 'What am I feeling?' The only acceptable answer is mad, sad, scared, or ashamed.
3) I let the feeling flow.
Feelings come and go pretty quickly. IIRC, usually they pass in seconds, but I don't remember what the research says about how long they can last. So one sign of being in a DT is that you're going on for hours. (Of course, I can even stretch a DT across days.)
I believe feelings after d-day (maybe after any trauma) can last for hours at a time, though I have no proof. In any case, duration of feeling bad may indicate pain shopping, but it's not definitive, especially in the early days.
After being betrayed, I expect it's almost impossible to avoid all DTs, but I also know from experience that they can be stopped by conscious effort when they're recognized.
When I was a new BS, and even now, one of the reasons I read SI was to help me get in touch with my grief, anger, fear, or shame. That's because I believe feelings are either felt or stored, and I don't want to store them. That works pretty well.
Equally important, being with fellow BSes helped me assuage the pain. We were all brother and sisters, and the 'older' ones (i.e. members with d-days that weren't as new as mine) showed us the way to heal.
Sometimes, though, I trigger badly, especially on over-generalizations, bad statistics, and disrespect toward SIers in R. When that happens, I get into a DT, and it's a challenge to respond with love. In fact, sometimes when I trigger badly, it's a challenge to stay within SI guidelines.
(Hmmm..iIt's taken me 6+ years to be able to put that into words.... Sorry, mods.)
In any case, I think it's accurate to say:
if you do something to confirm feeling horrible, you're probably pain shopping;
if you do something to get in touch with your own pain so you can feel it and let it go, you're probably not;
if you do something to help you through the pain and that something works pretty quickly, you're probably not.
Remember, though, being betrayed brings with it immense pain, much more than anyone can imagine, so if you think you're 'pain shopping', I'd be biased towards 'You're not.'
[This message edited by sisoon at 12:52 PM, April 19th (Wednesday)]