If your spouse/other half has gotten involved with someone else and the 3rd party has no idea that he/she has came in between, would you make it known to him/her?
Dunno how it will be perceived but I would think to make it known is not for revenge rather it's to let the 3rd party know so that he/she will not think that he/she is living in bliss? I mean, why not? Especially if you have been in living hell, why grant the 3rd party the indulgence?