Male viewpoint here.
No doubt this thread will get derailed into whether porn is non ethical and degrading to women etc but that’s not what this thread is about.
Porn releases different neurological chemicals to sex, and the two are very different . Porn is easy and takes little to no effort whereas sex is more about bonding with the other person. Its is really important to realise that a husband of BF that watches porn isn’t watching it because he doesn’t fancy you.
Porn becomes destructive in a relationship when it directly impacts the intimacy between the two concerned: in theory, if you were having sex every day, and he still watched porn 2-3 times a week then it likely wouldn’t be such as issue as you will not be losing out.
it is also important to realise that he won’t be watching it just 2-3 times a week, it will likely be daily. Is this a porn addiction? I’m not so sure, i watch porn daily but it doesn’t hinder my daily life and routine, and when in a relationship I can and do stop, as long as I’m getting the intimacy I need/want from my partner.
Having a sneaky wank when you went upstairs to bed instead of being intimate with you is worrying and if my partner did the same I would like you, be really upset.
Was he aware prior to this that you wanted sex more often than once a week?
I’m not sure if I read your post correctly, but did your DH watch porn whilst your 4 year old Ds was in bed with you? If he did then that is disgusting and would confirm to me that he puts his porn watching before the moral ethics of his family.