That MA is a no fault state is irrelevant. You are not trying to find a cause for divorcing him. Rather, you are collecting evidence that helps paint your soon to be ex in a negative light, to help outweigh your history of ETC and bad housekeeping.

If you can present your evidence in the couples meeting telling him "dude, you are finished. Let us agree to a sbared custody arrangement and let us decide to hire a mediator right now", then you just might luck out and save handsomely on the litigation fees. But you need to present your discov not as in "here is the evidence I have compiled - what has been going on?" But rather as "not that we were not already close to being done, but after these lovely findings we sure are done as I don't want to limit your exciting new life and, by the way, you should say bye to your hopes of getting custody of our son with that kind of record, so let us get into mediation asap"

Hopefully this shock would be a good moment to strike a deal. Then ask the couples T to recommend a divorce mediator. The T surely has a list of names.

Good luck! How many years of couples - 5? You could have invested the couples T fees into your new business. ..