[AnAmericanMother]

Not in a sexual sense. The sexual act (because of our fallen nature) is so compassed about with sin and temptation. It is better to remain chaste, so said St. Paul, and certainly in this situation Joseph as a righteous man would remain chaste rather than approach the Theotokos - the God-Bearer - in a sexual way.

No need to bring the sin of Adam into this - in fact the Virgin Mary is often contrasted with Eve - the second Eve, who did not fall and brought forth salvation.

[christianhomeschoolmommaof3]

Adam and Eve were husband and wife. Christ is the second Adam. Mary is not his wife but his mother.

[christianhomeschoolmommaof3]

Sex with your husband is not sinful and would not have defiled Mary.
The Apostle Paul said it was better to remain unmarried not married and chaste. The Bible actually warns us against denying our husbands sexually.