Is an incestuous kiss by a sister to her brother, indulged in once with desire, followed by repentance, considered incest that necessitates iddah (waiting period) or execution? Do her sexual fantasies about her mahrams invalidate kinship or necessitate iddah after repentance? Is her repentance accepted thereafter, or is expiation required? Is she then forbidden from being in seclusion with her mahrams? Does thinking about having intercourse with a non-Muslim constitute apostasy from Islam, is her repentance for it accepted, and does it entail iddah or expiation?

Enjoying unlawful intimacy with a mahram (a close relative with whom marriage is forbidden) is heinous, and true zina (fornication/adultery) is the penetration of the vagina into the vagina. Anything less than that is not true zina, but it is still forbidden. Whoever repents with a sincere repentance by abandoning the sin, regretting it, and resolving never to return to it, and covers herself, then Allah will accept her repentance. She is not required to perform istibra (waiting period) or kaffara (expiation), and she is permitted to be alone with her mahrams if there is no suspicion. Sexual fantasies do not take their perpetrator outside of Islam, but it is not permissible to dwell on them as they may lead to forbidden acts. Ibn al-Qayyim held that guarding one's thoughts is important because they are the origin of corruption. Correct repentance erases sin, and the one who repents is like one who has no sin.