His marriage is his business between him and his wife, no one else.
except we all know something she does not know and he has decided to play away so it is and it is not just between him and his wife as there is a big fat secret that will break the marriage
No idea what I would do re this but Graham seemed to get it as to whether your motives are noble or vengeance if the former possibly if the later no. I hate those who cheat dishonesty in a marriage is always a no go [ unless it relates to the cost of bike parts* ]
As for the “bird” stay away as she cannot be faithful and she is happy to sleep with married men…unless this is your perfect recipe for a “bird” in which case marry her.
* even that is wrong and she knows what I spend