Of the "fault"-based grounds for divorce in Massachusetts, adultery is probably the most complicated. Many individuals seeking a divorce wish to prove to the court that their husband or wife cheated, and therefore was not a good spouse. This certainly affords an opportunity for those seeking to air their soon-to-be ex-spouse's dirty laundry, even requiring the paramour to be named as a co-defendant. However, it requires proving the existence of an extra-marital affair, and finding out all of the details of an affair could be more hurtful than helpful to the faithful spouse.
Further, the defense of "condonation" has the potential to defeat a complaint for divorce based on adultery. In essence, this defense claims that the faithful spouse forgave the unfaithful spouse, and should be prevented from now seeking a divorce based on adultery. For example, let's say that Pat is married to Alex. Pat has an affair with someone at work. If Alex can prove that Pat had an affair, then Alex could obtain a divorce on grounds of adultery. However, if Pat wishes to defend against the complaint for divorce and remain married, Pat could use the defense of condonation if Pat can prove that after Alex learned of Pat's affair, Alex and Pat continued to live together and continued to have marital relations. If Alex was unsure about proving that the affair happened, or whether Pat could successfully defend by claiming condonation, and Alex really wants to obtain a divorce, Alex should file for a "no-fault" divorce instead.
There is no such defense to a "no-fault" divorce. All that is required is one spouse has to be able to tell a judge that there has been an irretrievable breakdown in the marriage with no chance of reconciliation.
In addition, adultery is still technically a crime in Massachusetts. This means that the defendant in a "fault" divorce based on adultery and the paramour can refuse to testify to any relations based on their 5th Amendment right not to incriminate themselves in a crime. This makes it more difficult to meet the evidentiary burden required to obtain the divorce and in the long run may not be worth the effort over the simplicity of a "no-fault" divorce.