133. It is forbidden you to wed your fathers' wives. # 107Marriage with one's stepmother is here explicitly prohibited. This prohibition also applies to marrying one's stepfather. Where Baha'u'llah has expressed a law between a man and a woman it applies mutatis mutandis as between a woman and a man unless the context should make this impossible.
Abdu'l-Baha and Shoghi Effendi confirmed that, while stepmothers are the only category of relatives mentioned in the text, this does not mean that all other unions within a family are permissible. Baha'u'llah states that it devolves upon the House of Justice to legislate "concerning the legitimacy or otherwise of marrying one's relatives" (Q and A 50). Abdu'l-Baha has written that the more distant the blood-relationship between the couple the better, since such marriages provide the basis for the physical well-being of humanity and are conducive to fellowship among mankind.
134. the subject of boys # 107The word translated here as "boys" has, in this context, in the Arabic original, the implication of paederasty. Shoghi Effendi has interpreted this reference as a prohibition on all homosexual relations.
The Baha'i teachings on sexual morality centre on marriage and the family as the bedrock of the whole structure of human society and are designed to protect and strengthen that divine institution. Baha'i law thus restricts permissible sexual intercourse to that between a man and the woman to whom he is married.
In a letter written on behalf of Shoghi Effendi it is stated:
No matter how devoted and fine the love may be between people of the same sex, to let it find expression in sexual acts is wrong. To say that it is ideal is no excuse. Immorality of every sort is really forbidden by Baha'u'llah, and homosexual relationships He looks upon as such, besides being against nature. To be afflicted this way is a great burden to a conscientious soul. But through the advice and help of doctors, through a strong and determined effort, and through prayer, a soul can overcome this handicap.Baha'u'llah makes provision for the Universal House of Justice to determine, according to the degree of the offence, penalties for adultery and sodomy (Q and A 49).