As Massachusetts is a no fault state, it is unlikely to make a difference legally in Massachusetts if you date discretely and are very careful about keeping your dating from your children.Most judges assume that one or both parties appearing before them in a divorce has already been unfaithful. Legally the judge can consider marital conduct, but as a practical matter unless it has been truly outrageous, or depleted family finances it is unlikely to make a monetary difference, but it could effect custody and parenting if children are exposed too early to new romantic interests.
But discussing legal implications really misses the point. Dating before your divorce is final may not have serious legal implications, but it will surely effect your negotiations. You have only one negotiating partner in your divorce, and it is your soon to be ex-spouse. Any dating activity, even if it is innocent, non-sexual, and casual, is bound to effect your soon to be ex-spouse emotionally. And that can cost you thousands of dollars in extra legal bills, and could effect the substantive provisions in your final settlement or court judgment. I always recommend that clients put off dating while they are negotiating their divorce. If it’s too late for that, then for Pete’s sake, please be discreet. Don’t rub your spouse’s face in it. That’s just common sense.