Oh now it’s a sin to not have sex?
In a marriage, yes.
Do you have a Bible?
If so, look this up: 1 Corinthians 7:3-5
3 The husband should fulfill his marital duty to his wife, and likewise the wife to her husband.God told Joseph to go on with his marriage plans with Mary.
4 The wife does not have authority over her own body but yields it to her husband. In the same way, the husband does not have authority over his own body but yields it to his wife.
5 Do not deprive each other except perhaps by mutual consent and for a time, so that you may devote yourselves to prayer. Then come together again so that Satan will not tempt you because of your lack of self-control. (NIV)
He also told him to wait until her pregnancy was over before having sex with her.
God's rules must be obeyed by married couples, or else it is a sin.
If Mary didn't have sex with her husband, it would have been a sin.
She was a very obedient handmaiden of the lord so would obey God.
You should study the Bible, it would help you answer many questions. Not that I mind teaching you scriptural Truths!
If you are married and you deny your spouse sex, do you not consider that wrong?
God does.
1 Corinthians 7:3-5 The husband should give to his wife her conjugal rights, and likewise the wife to her husband. For the wife does not have authority over her own body, but the husband does. Likewise the husband does not have authority over his own body, but the wife does. Do not deprive one another, except perhaps by agreement for a limited time, that you may devote yourselves to prayer; but then come together again, so that Satan may not tempt you because of your lack of self-control.