I am so sorry for what you are going through. If your ss hit you that is very serious in my opinion. I can't tell you what to do but I can tell you I know the "I will talk to him" speach from dh very well.
It does nothing at all! my ss does not live with us full time weekend and vacations. I have a bs also and when we were first married my ss behavior was a constant problem. disrespect to me, thinking the rules on applied to my bs etc. I had the option becasue he only came on weekends to seperate my bs from him.
He pushed my son off his bike, and my husband laid in bed and said nothing. I was so pissed for a while I sent my son somewhere else grandparents, biodads, on the weekends ss came.
I would have a long talk with dh if you can and let him know your fears for your biokids and why is it okay for any child or any person to hit you. I am sorry I don't have great advice but I just wanted you to know people are here for you

I went through this with my middle SD beginning when she turned 15. By the time she was 16 she had gotten to the point where she was so abusive that her older brother and younger sisters were scared of her. They were all teenagers at this time and my SS had graduated from high school and was in college, home on the weekends and holidays. That Thanksgiving at Thanksgiving dinner she threatened "I'm gonna cut you, you B****" when I told her to put her dishes in the sink when she finished her Thanksgiving dinner (which I cooked and cleaned up after). She did this in front of all of her siblings including my son who is her half brother. She did this in front of my family members and husband's family members. She then proceeded to stomp her butt into the living room. No one said a thing. When her older brother told her that wasn't a very nice thing to say she replied to him, "I'll kill you tonight while you sleep". No one said a word. It escaladed from there. When she went into the main bathroom (us grown ups were at the dining room table trying to exchange stories and so on) her older sister knocked on the bathroom door and told her to hurry up as she also needed to use the bathroom and then her older sister sat down in the recliner while she waited. Well, that girl came out of the bathroom and hit her sister in the face and then flipped the recliner over on her. My family left. My husband's family left. No one wanted to get involved, but they were shocked, but didn't feel it was their place to butt in. The girls got in a fist fight. The middle daughter then attempted to hit her older brother in the face, but that didn't work out for her, he just held her back. I told my husband he had to find somewhere else for her to go. Immediately. He drove around with her in his vehicle for hours trying to figure out what to do with her and finally put her up at one of her friend's houses for a couple of days. She came home after her brother left again for college. Then I had to deal with her.

She skipped school all of the time. The principle was after her, the truancy officer was after her, yet her father wouldn't do anything. These people were calling me at home and at work trying to get me to do something. I couldn't get anywhere with this and I told them so. The kid had big parties in my house if I went out of town. I had a brand new house and she destroyed a lot of the interior in a year's time. It was horrible. Anyhow, things got worse. One morning her younger sister opened my bedroom door on her way out to the school bus and told me "I've tried, but you have to deal with her again. I can't do it. She won't budge, yet, I know she is awake". So, I knew I would have to motivate her out of the house. I went in her room, told her to get up. Nothing. I yelled at her to get up. Nothing, but a smirk on her face as she lay there. I shook her toe and jumped back waiting for her violent reaction. Well, she came alive. She told me to "get the f*** out of my room you f***ing B****. How dare you come in my room you God Damn C***!" Then the verbal war was on. Anyhow, in front of my son who was hiding under the dining room table she kicked me, punched me in the face, broke my nose, my glasses, bruised me up all over the place. I stood my ground. I didn't hit her back. I just stood my ground. She didn't take me out thank God. Anyhow, as she grabbed her backpack and was heading for the door to "go to school" which she wasn't, but at least I had got her out of the house I informed her she wouldn't be coming back to my house and that her stuff would be out on the curb and her keys would no longer work in the locks of my house. She flipped me off and told me to "get f***ed. You can't kick me out of my house you f***ing B****!" Then she was gone. I knew my DH wasn't going to do a thing, and I no longer cared. My son had been under the dining room table the entire time screaming to his sister to "please stop hitting my Mommy!" He was crying. I told him that this would NEVER happen again. I have kept my promise. I called into work and told them I would be very late and that I might not make it in at all. Fortunately, my boss knew I had an out of control 16 year old at home. After calming my son down, I called the locksmith who appeared within the hour to change the locks on the house. During that time, and after I packed up all of that girl's clothing, and crap/belongings and deposited all of it on the curb. I then packed up my son and took him to daycare and I went to work. I looked like a man had beat the crap out of me. I no longer had my glasses, so I couldn't see very well, my nose was all swollen and my eyes were pretty dark, but, fortunately, not so bad as to have full on purple shiners. I was pretty swollen up, had a split lip and the ice wasn't working as good as I hoped it would have. Anyhow, my employer knew exactly what had happened and asked if I had finally kicked the rotten child out. I informed my employer I had and things got better from there. Anyhow, my husband was not real pleased as this upped the workload for him. Unfortunately, without me knowing it, he moved the rotten 16 year old SD into my rental house which was vacant at the time therefore creating me a landlord tenant relationship with his abusive daughter/my SD. It took me until she was 18 to get her out of that house. I could not get any rent, had to pay for her electricity, water, sewer, and provide her one meal a day according to state law. Lovely. When I did finally get her out it required the help of the Sheriff to remove her. The good thing-SHE WAS NOT LIVING IN THE HOUSE I LIVE IN WHITH MY FAMILY!!!!!!!!!!!!!!! That was the important thing. So, while it cost me a lot of money, I didn't have her ruining my life and my son's life and the life of the rest of the SK's. Also, my husband did learn a little "tough love" a long the way. He still isn't really good at it, but he is better than he used to be.

Do not wait to be hit again. There is never an excuse for that. NEVER.

I'm all for fighting for your marriage, and I know that "hitting" can mean many things from very light to very severe.

The bottom line is that a 16 year old boy is typically at least as big if not much more so than a full grown woman. I don't imagine your husband would allow any other man to lay his hands on you like that without retaliation. If your husband does not understand that he should protect you physically from an attacker then he needs to get his ass kicked. You also have young daughters to worry about.

Restraining Order????