Why are you asking your wife what HER plan is.. she has no plan, she's an ADDICT.
You set the pace of the marriage FOR her... you need to push her in two directions here... one of which she has to take, neither of which she will like
a. End her affair and attend family therapy to repair her marriage b. Leave her home, her husband, and her children for a reckless unproven unreliable man
She doens't like EITHER of those, she wants
c. Continue a taboo secret love affair with a married man
YOU put a stop to c, make sure she knows c is NOT available to her anymore, and then she has to go with a or b.