Privacy is closing the door when going to the bathroom. That is privacy. What he is doing is trying to confuse you on the difference between secrecy vs privacy. There are no secrets in a marriage or loving relationship. And you know what. He is deflecting. You know this.
There is no power struggle going on. What is going on is that your husband made some horrible mistakes that were thoughtless and extremely hurtful. He is lashing out to shift the blame. From where it should be. On his shoulders.
WTF. Why are you worried about him forgiving you. He is the one who has stepped out of the marriage with other women. He is the one who has zero respect for your child , stepchild and you. He is the one who is a liar and a cheater. He is the one who has zero respect for vows. Remember that every time you think you need him to forgive you. He is the one who needs to seek forgiveness.
You are better than this. And you know it. Do not fall into the mind games. Remove yourself from them. Allow him to come to grips with what he did without you around to deflect.
Flowers always make people better, happier, and more helpful; they are sunshine, food and medicine for the soul. unconditional love is awesome!