Although sex is the woman's right, she does not have absolute discretion to withhold it from her husband. A woman may not withhold sex from her husband as a form of punishment, and if she does, the husband may divorce her without paying the substantial divorce settlement provided for in the ketubah.
Niddah: The Laws of Separation
One of the most mysterious areas of Jewish sexual practices is the law of niddah, separation of husband and wife during the woman's menstrual period. These laws are also known as taharat ha-mishpachah, family purity. Few people outside of the Orthodox community are even aware that these laws exist, which is unfortunate, because these laws provide many undeniable benefits. The laws of niddah are not deliberately kept secret; they are simply unknown because most non-Orthodox Jews do not continue their religious education beyond bar mitzvah, and these laws address subjects that are not really suitable for discussion with children under the age of 13.
According to the Torah, a man is forbidden from having sexual intercourse with a niddah, that is, a menstruating woman. The law of niddah is the only law of ritual purity that continues to be observed to day. At one time, a large portion of Jewish law revolved around questions of ritual purity and impurity. All of the other laws had significance in the time of the Temple, but are not applicable today.
The time of separation begins at the first sign of blood and ends in the evening of the woman's seventh "clean day." This separation lasts a minimum of 12 days. The rabbis broadened this prohibition, maintaining that a man may not even touch his wife or sleep in the same bed as her during this time. Weddings must be scheduled carefully, so that the woman is not in a state of niddah on her wedding night.
At the end of the period of niddah, as soon as possible after nightfall after the seventh clean day, the woman must immerse herself in a kosher mikvah, a ritual pool. The mikvah was traditionally used to cleanse a person of various forms of ritual impurity. Today, it is used almost exclusively for this purpose and as part of the ritual of conversion. It is important to note that the purpose of the mikvah is solely ritual purification, not physical cleanliness; in fact, immersion in the mikvah is not valid unless the woman is thoroughly bathed before immersion. The mikvah is such an important part of traditional Jewish ritual life that a new community will build a mikvah before they build a synagogue.
The Torah does not specify the reason for the laws of niddah, but this period of abstention has both physical and psychological benefits.
The fertility benefits of this practice are obvious and undeniable. In fact, it is remarkable how closely these laws parallel the advice given by medical professionals today. When couples are having trouble conceiving, modern medical professionals routinely advise them to abstain from sex during the two weeks around a woman's period (to increase the man's sperm count at a time when conception is not possible), and to have sex on alternate nights during the remaining two weeks. When you combine this basic physical benefit with the psychological benefit of believing that you are fulfilling G-d’s will, it is absolutely shocking that more couples with fertility problems do not attempt this practice. The rejection of this practice by the liberal movements of Judaism is not a matter of "informed choice," but simply a matter of ignorance or blind prejudice.
Birth Control
In principle, birth control is permitted, so long as the couple is committed to eventually fulfilling the mitzvah to be fruitful and multiply (which, at a minimum, consists of having two children, one of each gender). The issue in birth control is not whether it is permitted, but what method is permitted, and under what circumstances.
Birth control is rather clearly permitted in circumstances where pregnancy would pose a medical risk to the mother or her other children. For example, the Talmud recognizes the use of birth control by very young women, pregnant women or nursing women. However, there is some variance of opinion as to what other circumstances might permit birth control. If this is an issue for you, you should consult a competent rabbinic authority.
It is well-established that methods that destroy the seed or block the passage of the seed are not permitted, thus condoms are not permitted for birth control. However, the pill is well-recognized as an acceptable form of birth control under Jewish law. I have also heard some say that a condom would be permitted under Jewish law to prevent the transmission of AIDS or similar diseases, because preserving the life of the uninfected spouse takes priority; however, I am not certain how authoritative this view is. If this is an issue for you, you should consult a competent rabbinic authority.
Abortion
Jewish law not only permits, but in some circumstances requires abortion. Where the mother's life is in jeopardy because of the unborn child, abortion is mandatory.
An unborn child has the status of "potential human life" until the majority of the body has emerged from the mother. Potential human life is valuable, and may not be terminated casually, but it does not have as much value as a life in existence. The Talmud makes no bones about this: it says quite bluntly that if the fetus threatens the life of the mother, you cut it up within her body and remove it limb by limb if necessary, because its life is not as valuable as hers. But once the greater part of the body has emerged, you cannot take its life to save the mother's, because you cannot choose between one human life and another.
Homosexuality
Sexual relations between men are clearly forbidden by the Torah. (Lev. 18:22). Such acts are condemned in the strongest possible terms, as abhorrent. The only other sexual sin that is described in such strong terms is the sin of remarrying a woman you had divorced after she had been married to another man. (See Deut. 24:4). The sin of sexual relations between men is punishable by death (Lev. 20:13), as are the sins of adultery and incest.
It is important to note, however, that it is homosexual acts that are forbidden, not homosexual orientation. Judaism focuses on a person's actions rather than a person's desires. A man's desire to have sex with another man is not a sin, so long as he does not act upon that desire. In fact, it could be said that a man who feels such desires but does not act upon them is worthy of more merit in that regard than a man who does not feel such desires at all, just as one who refrains from pork because it is forbidden deserves more merit than one who refrains from pork because he doesn't like the taste.
I have seen some modern Orthodox sources suggest that if homosexuality is truly something hardwired in the brain, as most gay activists suggest, then a man who acts upon that desire is not morally responsible for his actions, but I am not sure how wide-spread that opinion is. Essentially, it is equivalent to saying that a kleptomaniac would not be held morally responsible for stealing.
Interestingly, female homosexual relations are not forbidden by the Torah. There is very little discussion of female homosexuality in the Talmud. The few sources that mention lesbian relations say that they do not disqualify a woman from certain privileges of the priesthood, because it is "merely licentiousness." There is a surprising lack of discussion of such issues as whether lesbianism would be grounds for divorcing a woman without her consent or without ketubah. Rambam asserted that lesbian practices are forbidden because it was a "practice of Egypt" and because it constituted rebelliousness.
The Process of Marriage: Kiddushin and Nisuin
The process of marriage occurs in two distinct stages: kiddushin (commonly translated as betrothal) and nisuin (full-fledged marriage). Kiddushin occurs when the woman accepts the money, contract or sexual relations offered by the prospective husband. The word "kiddushin" comes from the root Qof-Dalet-Shin, meaning "sanctified." It reflects the sanctity of the marital relation. However, the root word also connotes something that is set aside for a specific (sacred) purpose, and the ritual of kiddushin sets aside the woman to be the wife of a particular man and no other.
Kiddushin is far more binding than an engagement as we understand the term in modern English; in fact, Rambam speaks of a period of engagement before the kiddushin. Once kiddushin is complete, the woman is legally the wife of the man. The relationship created by kiddushin can only be dissolved by death or divorce. However, the spouses do not live together at the time of the kiddushin, and the mutual obligations created by the marital relationship do not take effect until the nisuin is complete.
The nisuin (from a word meaning "elevation") completes the process of marriage. The husband brings the wife into his home and they begin their married life together.
In the past, the kiddushin and nisuin would routinely occur as much as a year apart. During that time, the husband would prepare a home for the new family. There was always a risk that during this long period of separation, the woman would discover that she wanted to marry another man, or the man would disappear, leaving the woman in the awkward state of being married but without a husband. Today, the two ceremonies are normally performed together.
The Marital Relationship
Marriage is vitally important in Judaism. Refraining from marriage is not considered holy, as it is in some other religions. On the contrary, it is considered unnatural. The Talmud says that an unmarried man is constantly thinking of sin. The Talmud tells of a rabbi who was introduced to a young unmarried rabbi. The older rabbi told the younger one not to come into his presence again until he was married.
Marriage is not solely, or even primarily, for the purpose of procreation. Traditional sources recognize that companionship, love and intimacy are the primary purposes of marriage, noting that woman was created in Gen. 2:18 because "it is not good for man to be alone," rather than because she was necessary for procreation.
According to the Torah and the Talmud, a man was permitted to marry more than one wife, but a woman could not marry more than one man. Although polygyny was permitted, it was never common. The Talmud never mentions any rabbi with more than one wife. Around 1000 C.E, Ashkenazic Jewry banned polygyny because of pressure from the predominant Christian culture. It continued to be permitted for Sephardic Jews in Islamic lands for many years. To the present day, Yemenite and Ethiopian Jews continue to practice polygyny; however, the modern state of Israel allows only one wife, unless you come to Israel with more than one wife, in which case you can keep the wives you have but you cannot marry new ones.
A husband is responsible for providing his wife with food, clothing and sexual relations (Ex. 21:10), as well as anything else specified in the ketubah. Marital sexual relations are the woman's right, not the man's. A man cannot force his wife to engage in sexual relations with him, nor is he permitted to abuse his wife in any way (a practice routinely permitted in Western countries until quite recently).
A married woman retains ownership of any property she brought to the marriage, but the husband has the right to manage the property and to enjoy profits from the property.
Jewish Attitude Toward Divorce
Judaism recognized the concept of "no-fault" divorce thousands of years ago. Judaism has always accepted divorce as a fact of life, albeit an unfortunate one. Judaism generally maintains that it is better for a couple to divorce than to remain together in a state of constant bitterness and strife.
Under Jewish Law, a man can divorce a woman for any reason or no reason. The Talmud specifically says that a man can divorce a woman because she spoiled his dinner or simply because he finds another woman more attractive, and the woman's consent to the divorce is not required. In fact, Jewish law requires divorce in some circumstances: when the wife commits a sexual transgression, a man must divorce her, even if he is inclined to forgive her.
This does not mean that Judaism takes divorce lightly. Many aspects of Jewish law discourage divorce. The procedural details involved in arranging a divorce are complex and exacting. Except in certain cases of misconduct by the wife, a man who divorces his wife is required to pay her substantial sums of money, as specified in the ketubah (marriage contract). In addition, Jewish law prohibits a man from remarrying his ex-wife after she has married another man. Kohanim cannot marry divorcees at all.