Bobby says he is “very worried” about his son’s behavior and what the 8-year-old may do to his fiancée, Chrysta, and the rest of his family. Bobby claims his son has been violent, started a fire in their home, and has tried to kill people.

TELL DR. PHIL YOUR STORY: Know someone with outrageous behavior?

Chrysta says she fears for her life and the safety of her two children. And, Chrysta’s mom and grandma say they want her to "run" from the relationship.

In the video above, Bobby describes what his son is like when he is not being aggressive and destructive.

WATCH: Ways Woman Claims Fiance’s 8-Year-Old Son Has Terrorized Her

“He would be nicer to a stranger and show more affection to him than he would one of us,” Bobby says.

Hear Dr. Phil’s response.

On Thursday’s episode, Dr. Phil offers his thoughts as to how Bobby can help his son. Check here to see where you can watch.

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