Bigamy requires SEMBLANCE with VALID marriage

The mere private act of signing a marriage contract bears no semblance to a valid marriage and thus, needs no judicial declaration of nullity. Such act alone, without more, cannot be deemed to constitute an ostensibly valid marriage for which petitioner might be held liable for bigamy unless he first secures a judicial declaration of nullity before he contracts a subsequent marriage. (Morigo vs. People, G.R. No. 145226, 06 February 2004, 422 SCRA 376)