I think need to act fast. As they seems didn't start yet,
but have feel towards each other.
How about write a letter to your husband, tell him that
you actually know something is happening
(don't make up any excuse la), but the wordings have to be 'gentle', don't 'chow dai wok'
ASk him whether he still love and care, precious you,
if yes, pls stop any contact with this woman,
tell him that if he can't even giveup a 'normal friend', still
keep contact, he will lost you.
Tell him that you understand so much about this kind of
relationship, any woman will feel inappropriate, not only
you, so don't ever say you are sensitive.(No Excuses)
In the letter, you should point out all the 'excuse' that
your husband might bring out, and firmly tell him that, it is not acceptable.
Ask him who is more important, his family(you) or a
simple friend(whether have feel or not), who will
definately destroy his family.
But remember, the word/tone should be gentle and
simpathetic, tell him how much you love him.......,
he like to protect woman ma, ask him whether he want
to protect you from being hurt.
But what you ask for(no contact any more) must stay
'firm'