Only God knows what would be in your heart, your neighbor's heart and the wife's heart. 99.99 percent of cases of adultery involve the severe infliction of pain on someone.
A caveat-- that figure would be lower if you don't count those so calloused they can no longer feel the pain.
I see. But in the .01 per cent case, your argument, I presume, is that Jesus said it was ok, because the law of agape love, as expressed in the Golden Rule trumps commandment against adultury?