Your ex will have their own private peep-hole into continually viewing your life, if they so desire. Especially if you rely on them for favors. Going on a trip? Be wary of asking them to water plants and feed your dog -- the temptation to snoop is extremely inviting.
It's wise to be sure the divorce is necessary, but if there's no hope for the marriage, letting go as gently and as quickly as possible will save the sanity and the assets of both partners and their children.
Most of the time, people respect the "divorce is hard" placard I carry and don't probe. But quite a few times I've gotten a certain response to my attempts to change the subject that has pissed me off.