I'm married male dragon 19 Dec 64 (wood) and my girlfriend snake 26 Nov 77 (fire). can last long?

I am a little confused. You are married and you have a GF? No offence, but are you having an affair? If so, I suggest you be loyal to your life. According to your DOB, you will only have one marriage in your life and you have a good wide. Cherish her! Objectively, you are not that compatible with your GF. Although you get along well in the beginning, there may be some arguments later.