From college and FaceBook....of course....I am hearing more and more of how FB is ruining marriages
Brother...I am not sure of your state of mind right now; I know how frustrating this can be.
However, we are to love our wife as Christ loved His church; so...what is love?
1Corinthians 13:4-7...Love is patient, love is kind. It does not envy, it does not boast, it is not proud. 5It is not rude, it is not self-seeking, it is not easily angered, it keeps no record of wrongs. 6Love does not delight in evil but rejoices with the truth. 7It always protects, always trusts, always hopes, always perseveres.
Now that is a mouth full; given your circumstances...love always protects, and does not delight in evil, and is not easily angered, and keeps no record of wrongs.
God calls husbands to protect their wife; from evil...from sin...from (in this case) another man!
With patience, humility, kindness...yet with conviction, protection, hope and faith...approach her, tell her you love her, want to protect her...and spill the beans with all you know. Truth will always set us free...
If you let this go...you are simply allowing a trap in which she will be caught, convicted and sentenced to a divorce...is that what you want?