It is important to note that not anybody could have sex with anyone. It had to be within acceptable limits, therefore sex was not allowed in the following ways and it was an offence of caught:

There were taboos and rituals when not even married people can have sex because it would bring misfortune e.g. when children have measles, brewing beer, burning charcoal! bricks.

Adultery was severally punished e.g. whipping, stoning spearing to death e.g. in Karamoja if a girl is discovered pregnant.

Fornication was not allowed in Ankole if one conceived before marriage she would be thrown down the cliff; while in Congo she would be tied on a tree in the middle of the forest for wild animals to eat her.

Incest was severely punished and some rituals had to be done to cleanse them e.g. among the Japadhola the girls would be made to lie on her back with legs open wide and the boy made to climb on top of the house and made to urinate in her private parts to create hatred.

Rape was punished in most cases with death.

Homosexuality was almost unheard of but in case it happened such would be an outcast.

Having sex with an animal (bestiality) was severally punished and the animal burnt to death.

Watching genitals of parents constituted an offence on the other hand in Karamoja if one looked at a woman's genitals and his penis erected he must ran very fast if not his penis would be beaten with a stick.

In most cases such offences needed cleansing (ritual) whether or not the offenders' one punished for fear of misfortune.

Marriage therefore is a religious responsibility for every one, focal point of 3 worlds; living, departed and those yet to be born. If one takes it up, produces children than the solemn duty has been accomplished.

The physical aspect of choice making, preparation, wedding. gifts are outside expressions of a religious happening (sacred understanding). 

Similarly aspects like virginity, procreation, polygamy, bareness, inheriting wives, divorce, use of sex, sexual offences are all religious experiences for any normal person to participate in.