Thanks for getting my point and not being a 'King Solomon'-waving or 'think of the child support!' dipshit, like most of the others here.
This is not a "women's body"-issue (as actual pregnancies may be construed as), but one of multiple sane adults enabling a postponed decision. Gender is irrelevant here, the subject is irrelevant and philosophically speaking, the number of parents is irrelevant as well.
The pre-embryos are not alive yet and the situation is thus equivalent to owning pretty much any inanimate objects with multiple people. The only slightly complicating matters are that the objects are very rare and irreplaceable, yet non-liquidatable. They could be inherited frozen T-Rex eggs: the problem (and answers) would remain the same.