Bed courtship is practiced only by the ultra-conservative churches.
The parents rely on the church teachings to prevent hanky-panky. The custom was practiced in Europe for centuries before immigrants introduced it to the American colonies.
The boy makes the long buggy trip home in the wee hours of the morning.
If both are willing, the couple starts going steady. On the weekend when there is no church, the couple usually dates on Saturday night. Either party can quit the relationship at any time.
So in these households, the old reasons for bed courtship remain.