Congratulations on the Championship victory! Nothing like that to build up a kid's self esteem...I'm sure you are very proud.
As far as any confrontation with or "outing" of the OM, politician or not, this will accomplish nothing. He is only the symptom and a bystander brought into this by some seemingly random, yet not so random, series of events/coincidences. The other person in our spouses EA's and PA's are selected by our spouses, even if our spouses did not do the persuing, so, it's best not to waste our energy seeking revenge for them.
Let's face it, if your W is anything like my W, they control all access to their emotional and physical beings...so, OM was GRANTED access and for that, he should not suffer. This is your W's issue...and for every OM you could possibly shame in to staying away from your W, SHE will find a replacement until SHE realizes that SHE has had enough (if and when that day comes).
Things do eventually catch up to people like this but it is not our job to accelerate karma...let it be.