Godd thing you are trying. In 1633 I explain that "Until" is but one possible translation for "eos". Another translation we frequently see is "till" or even "even to the time that". See, for example, Matthew 27:8 "the field was called Haceldama, that is, The field of blood, even to this day". This is why there is nothing in Matthew 1:25 to indicate anything about Joseph and Mary after the birth of Christ.
Try reading Matthew 1:24 and 1:25 in context. Its very illuminating.