Yes, speak with a divorce attorney right away.  Your wife is attempting to black mail you with all of this.  And although I do not myself condone it I will not judge what happened here.  I am only here to tel you that in this day and age adultery is not necessarily taken in to account in determining matters in an action for divorce.  Meaning that it will not necessarily have any effect on alimony or asset distribution.  And you seem to still care about your wife on some level with not wanting to tarnish her image in any way.  I would not advise you to in any way black mail her with that information either, but let her know that you would prefer not to have any of the circumstances surrounding your divorce made public to anyone and especially how you met this woman.  PS  Your wife has to prove adultery if she alleges it.  Not an easy task.  Good luck.