According to the gospel of Matthew, when did Joseph "know" Mary?
Sometime after Jesus was born
Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife:
And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
Matthew 1:24Now the birth of Jesus Christ was on this wise: When as his mother Mary was espoused to Joseph,
before they came together, she was found with child of the Holy Ghost. Matthew 1:18
Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife:
And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
Matthew 1:24