Hey!! 

So now that you know that it was wrong, think about what can be done rather than what you did.

You can always confess and deal with the consequences or not tell them, and deal with the situation. Either ways you wouldn't have it easy. You cannot have them both, and sooner or later they will come to know.

May be your wife would leave you, or may be not, thats up to her. But I think she deserves to know! and its the same way with the other girl! and besides if you live with a lie, you wouldnt have that piece of mind, your guilt will always kill you within, thats if you regret doing things you did.

Rest is up to you!