<human>: My mom just got married to a guy she's been dating for a couple years, and recently his actions have been making me uncomfortable.
Whenever we're alone he'll try to discretely touch my ass. When I ask him not too he insists that it's ok because we're friends, but then when I make an effort to not be friends with him he gets really angry at me. A while ago when I wasn't acting how he wanted me to, he pointed a pocket knife at me (I'm terrified of knives and I didn't know the knife was dull) and then stabbed me in the leg with it. It was too dull to even poke me, but it actually really scared me. 
Even when I bring up the issue around my family everyone acts like it's normal. My stepdad laughs about it and pretends it's completely acceptable for him to touch me like that.
He's also made a few inappropriate comments toward me recently. He always tries to bring up my sex life (which he knows nothing about) and my alcoholism (I don't drink at all). A while ago when he was drunk he told me when we were alone that he'd rather be with me than my mother. I left without saying anything to avoid encouraging his inappropriate behaviour, but I don't think he's understanding that he's making me really uncomfortable.
I can't talk about this with any of my family members because I'm not very close with any of them. I've asked my stepbrother to talk to him about it but he doesn't think this is very serious either.
Am I not making it clear enough that I find this very inappropriate? Am I over-reacting to a parenting style that I just don't understand? What should I do to make him stop?

Can you give me a shortened version of the text?
<bot>: My stepdad has been making inappropriate comments toward me and touching my ass and my family is acting like it's normal.