Among the only opportunities a hard-time prisoner would have to engage in sexual relations or intimate visitation with one of the opposite sex (usually his/her spouse). Does not always have a sexual connotation, but in this case, it almost always does.

Of or relating to the marital relationship or to the relationship between a wife and husband.

Visiting your partner who is currently in prison to have sex with them. Conjugal visits often motivate inmates to maintain good behavior.