And now we're back to where we started. Do you read what is posted to you? Mutually agreeing to not have sex is not a sin. You can go through the whole cycle of posts again, like you are prone to do, but you have no proof that mutally agreeing to not have sex is a sin.
Why would Mary or all people of placed her husband or herself in a position to be tempted by Satan?
You assume Mary was withholding sex from Joseph, who requested it. You assume Mary and Joseph could not make a mutual agreement to not have sex. You assume that Mary and Joseph had no self control. By your question, you must assume that Mary did not abstain from sex before the birth of Jesus.
The Bible, which is the very word of God, makes it clear that the marriage was consumated.
Matthew 1:24 Then Joseph being raised from sleep did as the angel of the Lord had bidden him, and took unto him his wife:
25 And knew her not till she had brought forth her firstborn son: and he called his name JESUS
There is no reason at all to believe that Mary or Joseph sinned by with holding sex from one another or that they never had sex.
The Bible says that they did not have sex until AFTER the birth of Jesus.