The best interests of a child could be undermined by living with a morally unfit parent. A court might deem a parent morally unfit due to substance abuse, casual sexual relationships with multiple partners, violence, emotional abuse or engaging in illegal activities. These alleged actions may be viewed in relationship to how they affect a child and perhaps jeopardize a child's moral and ethical development. For example, a parent who committed adultery might only have that behavior affect a custody decision if the child was openly exposed to the activity.