I think the OP (correct me if I'm wrong) is looking for validation that it's abuse. For someone who's never been abused, has been brought up in a healthy family with good boundaries, you are aware of bad behaviour. Unfortunately, when you've been brought up in an abusive family, you have no idea of healthy and unhealthy behaviour because abuse is all you've known. It's why so many Adult Children get into abusive relationships because that's their 'normal'.
The OP has only known her husband and has been with him from teenage years so that is her 'normal'. Now there are loads of people saying 'he's an abuser!' and she's checking in to see if behaviour she doesn't like is wrong and abusive.
I hope that makes sense and I hope you don't mind me talking for you OP and if this is not your experience, then please correct me. You've had enough people in your life telling you what to think and feel, I don't want to become part of that.
I'm just trying to clear up the confusion others have of why you seem to be minimising or unsure of whether or not something is abusive or wrong.
I'm concerned about him asking your permission OP as I'm wondering where that has come from. It's unusual for him to ask before he assaults you. However, the rest is typical of his sexually abusive behaviour. He has no right to dry hump you, grab your bum, make demeaning comments about you to the children (that's abusive to them as well) or act in an aggressively sexual way in front of them (that's also abuse). They are also learning that no doesn't mean no and women have no rights to their bodies.
I'm sorry you're having to put up with this, no one should. Please call the police should you believe he's going to go further or you're in danger. In the meantime we can only wait for WA and start getting a plan underway to remove you and the children safely from the situation. You need to log the behaviour as well, which you are doing.
We have also discussed a safety plan should you need to flee. Keep your car keys and phone with you. Phone on charge. Money on hand and your route planned. Get away and dial 999. Manoeuvre arguments away from the kitchen and don't go to the bathroom. Keep yourself and the children somewhere where there is an escape route.