I nursed our daughter for 11 months, and it really did mean access-denied for my husband. Just as I suspected, I couldn't fathom switching from functionality to eroticism. There was no dual usage there. I was very sensitive to giving them back to him, for fear that any "activity" would prolong milk production. In truth, his access was revoked for at least a year if not a few months more. Slowly, though, life—and my body—returned to its previous state.
What about me? When do they become mine again? Probably when no one has any use for or wants to be within ten feet of them—when I'm 70. I kid. When you think about it, they've been mine all along, in a way. I certainly received pleasure from my husband's "use," while I definitely benefited from providing for and comforting my daughter. Turns out, they were a vessel for my own happiness all along.