Every time the phrase is used in the Bible it is talking about intercourse.
Genesis 38:26 And Judah acknowledged them, and said, She hath been more righteous than I; because that I gave her not to Shelah my son. And he knew her again no more.
Judges 19:25 But the men would not hearken to him: so the man took his concubine, and brought her forth unto them; and they knew her, and abused her all the night until the morning: and when the day began to spring, they let her go.
1 Kings 1:4 And the damsel was very fair, and cherished the king, and ministered to him: but the king knew her not.
Matthew 1:25 And knew her not till she had brought forth her firstborn son: and he called his name JESUS.
I am not talking about "knowing". I am talking about "till"...
"Matthew 1:25 And knew her not till she had brought forth her firstborn son: and he called his name JESUS
The Greek Septaugint uses the exact same word in Matthew 1:25 as in 2 Samuel 6:23
"Therefore Michal the daughter of Saul had no child till (unto) the day of her death."
Are you going to propose to me that Michal had a child AFTER her death? As Kosta says, the Scripture does not necessarily discuss the FUTURE when using "til" or "unto". It is YOUR presumption that Mary had sex with Joseph. The Bible is silent on that. Thus, we rely on Apostolic Tradition to tell us that Mary remained a virgin. The Bible alone does not tell us either way.
Regards