Why can't we share a room on the winter solstice?

The solstice in winter and the solstice in summer are the times when yin and yang change. The movement of qi in heaven and earth is relatively active, but the human body is in a relatively weak state. Therefore, it is best not to have sex in these two days and a few days before and after the winter solstice. On the one hand, it will consume your energy; on the other hand, the quality of Xue Jing is unbalanced. If you are pregnant, your child may be eccentric.