"But he did not consummate their marriage until she gave birth to a son. And he gave him the name Jesus." (Matthew 1:25) NIV
"And knew her not till she had brought forth her firstborn son: and he called his name JESUS." (Matthew 1:25) KJV
γινώσκω ginōskō know
BDAG know, know about, make acquaintance of; learn (of), ascertain, find out; understand, comprehend; perceive, notice, realize; have sex/marital relations with,; have come to know, know
Louw-Nida to have sexual intercourse with
DBL Greek know; learn; be familiar with; understand; acknowledge; have sexual intercourse
LEH LXX Lexicon to come to know, to perceive; to know; to recognize; to form a judgement, to think; to acknowledge as true; to know carnally
LXGRCANLEX know; to know; to have sex; to know; to learn; to know
The Lexham Analytical Lexicon to the Septuagint know; perceive; learn; ידע; know; ראה; see; דַּ֫עַת
So based on the original Greek, there are only two options. Either the NIV is correct in its translation or Joseph was a complete stranger until Jesus was born. Since the later is obviously incorrect and contradicts scripture, the only version that sticks it consummate.
I guess Mary not consummating the marriage until after Jesus was born means that Mary never consummated the marriage?