The man allegedly subjected a boy under the age of 15 to serious sexual abuse on several occasions over six months, starting last Christmas.
According to prosecutors, the man has abused a special trust because the victim is considered a relative.
The crimes must have occurred in Halland and the Stockholm area.
For one incident, the man is charged with child rape.
A 35-year-old woman is also charged with inciting serious sexual abuse and rape of a child.
According to prosecutors, she encouraged the man to carry out acts and wrote to him what to do.
Both the man and the woman deny wrongdoing.