If that's what was in your heart, then it's always good to convey it. It's authentic.
As for telling the kids, HE'S going to have to own that, you do know that, right? You should be there with him, and answer any questions that your kids have, but HE NEEDS TO DO THE TALKING. And tell him ahead of time, that you're NOT going to put up with any "we" language if he tries to put this off on BOTH of you. Your position towards your kids needs to be "This is what your dad wants. It's not what I want, but I have to respect his choice. We both love you very much, and this is NOT your fault," etc.
