Whatever you do, don't just blurt out the d-word, especially if the children have been pretty much clueless about what has been going on. Think through everything and plan out the conversation.
There are three basic questions for guiding parents through how to tell their children:
1. When are you going to tell them?
The typical recommendation is that you and your soon-to-be-ex tell your children together and at the same time. With adult children who are no longer living at home, this may be harder to do, so you have to think through these logistics and plan properly.
2. What are you going to tell them?
The typical recommendation here is to keep it simple and avoid the details of who did what. That advice still holds true although it can be harder to follow with adult children who may have more of an awareness of what has been going and who will certainly have their own opinions which they will want to express.
3. How will the divorce impact them?
Adult children aren’t going to be moving between two homes but they will want to know what your divorce means to family Holidays and vacations, the family home, and any of the ways you are currently supporting them such as going to college or helping with grandchildren.
Divorce always means having to renegotiate your relationship with your child so they see you as an individual rather than ‘mom and dad.’ This happens even if you and your ex are parenting as a team. This renegotiation is harder with adult children. If they are no longer living at home, then just the physical separation means less contact. Your children’s lives may already be full and they may have little time to support you. It’s going to be up to you to take the lead here to create the opportunities for more interaction and to make the effort to make this happen.