Step kids

Do you feel its best to be a parental figure to your step kids or do you feel that you should be their friend? I am a parental figure because i have been involved since my step kid was less than a year old. Also my OH wants his child to listen to me when he is not around. We have similar parenting styles almost to the point of them being exactly the same so he agrees with anything i tell his child to do. He also enforces that his child listen to me at all times and agrees with my rewards and punishments.