As long as you are both members of the LLC (i.e., one does not drop out or otherwise leave the LLC), and you do not reside in a community property state, you cannot file as a single-member LLC; you need to file a 1065.
Of course, if the LLC has neither income nor expenditures for the tax year, it is not required to file a return.
See https://www.irs.gov/instructions/i1065#idm140672607580960
