Yes, sologamy is legal in the strictest sense of the word. There are no laws against the practice in any of the fifty states in the US. You cannot be arrested or fined for marrying yourself. Individuals are free to make commitments to themselves at any time they choose. In fact, personal goals and resolutions are made and broken by individuals daily without legal implication. (No, you can’t sue yourself for breach of contract.)”
Moreover, ceremonies can be optional; according to the writer “You can have what is known as a 'self-uniting' marriage, which