About a wedding

I have a question that I can't get a clear answer. Two of our American born Filipino friends are getting married. My bf is Filipino and we've been together for over 6 years. When the couple sent out the invitations, only my bf was invited and I wasn't included. He did ask to bring me but they said no. The couple knows that me and my bf are together and we are all friendly towards each other. According to my bf, they have decided to follow Filipino wedding traditions and only invite those they are truly close to (they've known him for over 20 years and me for a long as I've been in the picture). Is that a real custom and should my bf have fought harder to get me invited? Please help