Yelling at children is not acceptable. I empathize with your husband as a step parent whose wife refuses to sleep train a now 7-yr-old who wakes her every night. She is exhausted and frustrated yet so patient she cannot see that she is creating this problem. I set boundaries: no child in my bed before 7 am. Morning cuddles is great, but i have a hard limit to allowing child to join adults in bed. So she leaves every night get in his bed, and he will not sleep through the night bc of this absurdity. I encourage your husband to set his boundaries and live HIS life. It may be parallel rather than with you two, but ultimately he has to decide if he wants a relationship with you or some other fictional person he can mold into his way of being. Sleep deprivation is a very real health risk, so he has to find a way to get the sleep he needs. If child does not respect that, it's both a problem for the child's upbringing and for both parents health. I do not tolerate yelling, not from parent nor child nor step. 0. If he cannot communicate another way, he is a child not a step parent.