Yes they are.
They always emotionally abuse them, because narcissists lack empathy. Some physically abuse. It depends on the specific case.
Males abuse or sexually abuse their children more than women, but there are a few cases where women sexually abuse their sons, but can be verbally or physically abusive by slapping, shoving towards their children.
This is very wrong but three ways parents abuse their children are physically, sexually or emotionally.
The likely word is the verb "molest" (to harm, or to sexually abuse).
If you've been exposed to narcissistic abuse in childhood, you're more likely to end up with narcissistic partners if you haven't worked through your abuse. Adult Children of Narcissists (ACONs) have a number of issues to resolve.
The plural term is spelled "molesters" (those who sexually abuse children).
Adele Mayer has written: 'Sex offenders' -- subject(s): Sex offenders, Rehabilitation 'Child Sexual Abuse and the Courts' -- subject(s): Child abuse, Child sexual abuse, Law and legislation, Psychological aspects, Psychological aspects of Sexually abused children, Sexually abused children 'Sexual abuse' -- subject(s): Child abuse, Child sexual abuse, Incest, Paraphilias, Pedophilia, Sex Offenses, Sexually abused children, Child Abuse 'Incest' -- subject(s): Incest victims, Psychotherapy, Sex offenders' spouses, Family relationships, Sex offenders
Peedo or Paedophile - some one who likes to sexually abuse children or has obsessions with them. (Urban Dictionary)
Throughout history, it has always been more likely that a man will sexually abuse women. However, many rapes and abuse often go unreported.
Abused children are likely to feel alienated from their parents, but alienation is not itself a form of abuse, it is just a consequence of abuse.
If the step son is young enough, he will follow the narcissitic route. narcissitic people can be dangerous for young children too because they are more likely to abuse them. You can find better males to choose from at church. Don't settle for less.
Sexually Abuse it.