The article says the Totten Trust’s name doesn’t come from the fact that they are established for tiny tots (though many are), but following a New York court case from 1904 (Matter of Totten)where this trust arrangement was first approved.
While the depositor is still living, he or she has compete control of the account and can spend all of the funds and change beneficiaries however he or she may choose. The beneficiaries have no rights until the depositor dies. Forbes explains that a Totten trust can be “a useful way to keep otherwise ungrateful heirs in line, for fear of becoming former heirs.”
So secret paramour or not, visit with your estate planning attorney and discuss how this trust and the others mentioned by Forbes might be helpful in your situation.