Let me see if I understood right: you are Pinay. You have a boyfriend who is an American. This American had once been married to another Pinay. They were married in the Philippines but they have since gotten a divorced in the US.
You are now wondering: whether you and your boyfriend can get married in the US; whether or not you can marry even without having your American boyfriend’s first marriage annulled in the Philippines; and whether or not you can be criminally charged by your boyfriend’s first wife.
Tama ba? Here’s the law:
1. The law on marriages in the Philippines applies only to Filipino citizens wherever in the world they may be found.
2. Your boyfriend is American. He got married to a Filipino woman in the Philippines but he has since gone back to the US and gotten divorced there. That divorce severed his marital ties with his first wife. Kasi, he is American and American law allows their citizens to obtain a divorce and to remarry even after a divorce. So, the divorce is effective as to your boyfriend who is an American.
3. To your boyfriend’s first wife, the divorce will not be so effective. Kasi, she is not an American citizen, she is a Pilipino citizen – Philippine laws do not allow divorce. So, the poor Filipina will be unable to remarry. But her American husband is free to remarry.
4. Since your American boyfriend wants to marry you in the US, where his government recognizes his divorce, he is free to marry you there. He may not be free to marry you in the Philippines, though, until he has successfully registered his divorce with the NSO in the Philippines. But, you can marry in the US.
5. As for criminal charges, since you will marry your American boyfriend in the US, the criminal laws of the Philippines cannot reach you there. We simply do not have the resources to enforce Philippine laws anywhere else in the world (kung sa Pilipinas, hirap tayong i-enforce ang ating mga batas, lalo pa kaya sa labas ng Pilipinas?)
As for your question regarding migration to the US, I think mas mabuti kung sa isang American immigration lawyer ka magtanong at komunsulta. Here is what little I know about US immigration laws:
1. You can get a fiancée visa. Your American boyfriend in the US will sponsor you. You are given a time period within which to marry your boyfriend. Under this visa, you are still single when you leave the Philippines but you will go to the US to marry your boyfriend.
2. You can also get married elsewhere in the world and apply for a partner or spouse visa. This means that you are already married when you apply for this visa.
3. Whatever you choose to apply for, you must have sufficient proof of your relationship (letters, emails, photographs or a common child). A common bank account or a common or joint credit card is also helpful to establish a life together.
4. There are certain “red flags” that the US immigration services look for: if there is a large age gap between the US citizen (sponsor) and the fiancée or spouse (especially when the woman is a lot older than the man); when the spouses are of different races and when the spouse or fiancé is of a targeted nationality (Filipinos are one of those targeted nationalities, not because of any suspected terrorist links but because of our propensity to become undocumented aliens in the US).
5. You will certainly be referred to a marriage fraud investigator. They are very intrusive in their questioning. You must be prepared to answer even those questions that can make you very uncomfortable (they ask very detailed questions about your love life, your sex life, etc. and you and your spouse/fiancé will be interviewed separately as well as together. Your stories must match essentially but not in every single detail.
Good luck to you! I hope I answered your questions.