How should a child address their stepfather?

It depends on their relationship, and how old the child is. It also depends on how well the child knows their biological father.

As Dad that's what I call my stepfather and my stepmother Mum because they took me away from a very bad stop and I love them for that and for all they have gone through taking care of me some thing my real parents didn't do yet abused me. Made me feel worthless just something to punish for what went wrong in their lifes. I'm glad I was adopted my prays for help was answered. God is the greatest and my step parents are too ☺

Or the Dude

Master or lord

If they are old enough to talk whichever, they (the child) feels comfortable. It isn't for the parent/stepparent to decide what the stepparent is called.

Mr. is too formal for a family member and Dad is a sacred relationship so definitely Sam

Cuck.

just because you are fucking my mum, you are still a dipstick