I would not tell your W. It isn't an on going affair and you have vowed not to let it happen again. What good would it cause to make her feel like cr*p?
Why are you thinking of telling her? Is it to make yourself feel less guilty?
If you tell her, you risk losing your marriage. Is it worth it?
I think you should keep quiet and resolve not to let it happen again. Confess to a shrink or a member of the clergy if you need to tell someone. Don't lay it on your wife.
