GOOD FT = Good Family Therapist - a family therapist WITH INFIDELITY background... many offer to help but they haven't researched infidelity at all... they are useless to you

Exposure can be as much as you need to get the affair overwith. If just telling her parents will do it, then that's all you need...

I think you need to decide how serious the EA is.. if you feel its a threat I would at the very least tell her co - workers...

IF she gets fired, but you aren't the one who told.. oh well...

Exposure is a judgement call on your part... for me I only had to expose to my wife's brother and a couple friends...

It sounds like her coworkers would be a good place to start... make sure you have PROOF... she will DENY the affair... they always try to deny it