What is a short summary of the story, Sleepwalking, in the collection, Come to Me?

In the story, Sleepwalking, Julia Sampson is married to Lionel Sampson who has a son, Lionel Jr., nicknamed Lion, from a previous marriage. Lion is 19 years old and had become Julia’s stepson 12 years earlier. Lionel and Julia have a son together as well, Gabriel Tyner Sampson, nicknamed Buster, who is still in elementary school. After Lionel’s death, the grieving family leaned on one another until the contact became too personal. One night when Lion and Julia were both feeling sad, Lion climbed into bed with her for comfort. He has sex with her, and she is a willing participant. After that, she realizes the mistake she has made, breaks his heart, tries to send him away, but he doesn’t leave and becomes disrespectful and hard to handle until he returns to school out of town. Lionel’s mother, Ruth, is shocked at her grandson’s change in attitude and personality, though she does know the reason why. After Lion leaves, Julia and Buster continue their lives normally.