Hello,I'm petitioning my mother to come to US.My income isn't enough so my fiancé is willing to be a co sponsor.I moved in with my fiancé 2 years ago,we file our taxes separately,I'm ready send my affidavit of support but I'm confused which one does he have to fill?I-864 or I-864A?or both since he is joint sponsor and also a household member?TIA!