Sex according to the order of the guru

[Bhakti Vikasa Swami]

TRANSLATION
All the rules and regulations apply equally to the householder and the
sannyasi, the member of the renounced order of life. The grhastha, however,
is given permission by the spiritual master to indulge in sex during the
period favorable for procreation.
PURPORT
It is sometimes misunderstood that a grhastha, a householder, is permitted
to indulge in sex at any time. This is a wrong conception of grhastha life.
In spiritual life, whether one is a grhastha, vanaprastha, sannyasi or
brahmacari, everyone is under the control of the spiritual master. For
brahmacaris and sannyasis there are strong restrictions on sexual
indulgence. Similarly, there are strong restrictions for grhasthas.
Grhasthas should indulge in sex life only in accordance with the order of
the guru. Therefore it is mentioned here that one must follow the orders of
the spiritual master (guru-vrttir vikalpena). When the spiritual master
orders, the grhastha may accept sex life. This is confirmed in Bhagavad-gita
(7.11). Dharmaviruddho bhutesu kamo 'smi: indulgence in sex life without
disobedience to the religious rules and regulations constitutes a religious
principle. The grhastha is allowed to indulge in sex life during the period
favorable for procreation and in accordance with the spiritual master's
order. If the spiritual master's orders allow a grhastha to engage in sex
life at a particular time, then the grhastha may do so; otherwise, if the
spiritual master orders against it, the grhastha should abstain. The
grhastha must obtain permission from the spiritual master to observe the
ritualistic ceremony of garbhadhana-samskara. Then he may approach his wife
to beget children, otherwise not. A brahmana generally remains a brahmacari
throughout his entire life, but although some brahmanas become grhasthas and
indulge in sex life, they do so under the complete control of the spiritual
master. The ksatriya is allowed to marry more than one wife, but this also
must be in accordance with the instructions of the spiritual master. It is
not that because one is a grhastha he may marry as many times as he likes
and indulge in sex life as he likes. This is not spiritual life. In
spiritual life, one must conduct one's whole life under the guidance of the
guru. Only one who executes his spiritual life under the direction of the
spiritual master can achieve the mercy of Krsna. Yasya prasadad
bhagavat-prasadah. If one desires to advance in spiritual life but he acts
whimsically, not following the orders of the spiritual master, he has no
shelter. Yasyaprasadan na gatih kuto 'pi. Without the spiritual master's
order, even the grhastha should not indulge in sex life.

Srila Prabhupada
--SB 7.12.11