I guess that letting go, but remaining open, is all we can do. Anything which seems to force a choice, even if this was not intended, is likely to result in a choice we don't like.
I've heard it put something like 'standing by, no longer vital to you, but available, looking on with pride in your achievements'

    Relationships don't end in these circumstances, but they do change, hopefully to something natural and live afirming. As a man, I don't think we ever let , or want to let, go of our mums.