I don't know whether he has started acting like this again and I've just not realised or if he is sensing something as yesterday I felt like I was treading on eggshells again and I've not felt that way in a while really.
Because abusers like him don't change and now his mask has slipped.
He isn't only sexually assaulting you, he is doing so in the presence of your children because it excites and aroused him. He is turned on by both your discomfort and the fact your children could (and do) witness him sexually assaulting you.
There is no reason good enough for you to still be living with this man and your children under the same roof.
They are living in an abusive household full of coercive control, sexual assault, sexual abuse (exposing children to sexual behaviour is classed as abuse of THEM) and previously (and inevitably again in future) their mother being raped by their father.
Do you honestly think it is fair on your children to live in this home?
Living in a refuge, and staying there this time, and relying on benefits in the short, medium or even long term is preferable to living with a rapist aroused by exposing them to sexual assault.