God bless you. My wife currently is having an affair and I believe divorce will result. I suggest you take steps to determine if he is actually having an affair, if possible. If he is it will be hard to ever trust him again. I can not say what to do next, that must come from much prayer and possibly professional advice. I share your pain, it is a very self-centered act to commit adultery and cause someone you love so much torment. I will never understand how this can happen between to people who have joined in love and share so much together. Ask God to give you the strength not to take revenge by having your own affair, this will cause you even more pain as you will have sinned against God's law. I have been tempted along these lines myself but thanks be to God his soft voice continues to whisper that this is not the way. I must wait for what God has in His plan for me, I must follow His will and not my own. I believe you will feel even more pain if you give in to the temptation to go outside your marriage; the infidelity must first be proven and the marriage covenant be broken before you seek the love and passion of another. This is God's law.
Heavenly Father, this day I pray for those of us tormented by the hideous acts of adultery committed against us, that You carry us through this time of heartache and instill in us the faith to believe in our hearts that what You have waiting for us, by Your grace, is a better place. I pray that You speak to Proverbs when she is tempted to go outside her marriage with Your soft voice, tell her this is not what pleases You, and will, therefore, be so very unfulfilling for her. Keep her in Your grace so that she will have the strength to resist this temptation. Lord I ask that You reveal the true nature of Proverb's husband's activity to her, if it is not as he says. I pray You guide her to make the best decisions regarding her marriage and that these decisions align with Your teachings and Your plan for her happiness. In Jesus' Name I pray, Amen