I am glad most writers here are not advocating severe punishments for adulterers. God makes bad things work together for the good. Adultery is devastating. But maybe the weak and shallow one needs the prayers of the offended one, and maybe that is a big part of the personal calling of the offended one - to pray for the one that offended him/her. Perhaps no one else would have spent their life praying for the salvation of that soul. In the eternal picture, the salvation of that soul is actually more important than the offense suffered.
It seems impossible when one is so deeply wounded to advocate for the offender, but with God all things are possible. He always gives the grace needed to do His will, and in instances like this, where much grace is needed, much grace is given.