AIBU for not wanting my partner to watch porn?

The world is pretty much divided into people who think porn is OK and those who don't. Typically more men in the former group than women. If you're in different camps, all you can really do is talk it out and see if you can change his perspective. You probably won't tbh, because unless he's never heard of the issues before, you cam assume he knows them, but puts his desire to use it ahead of that. You can extract promises he won't use it, or issue ultimatums, but that tends to drive it underground. So I guess if a talk doesn't change his mind, you need to consider if you can live with this in your life or not.

Well yes, you chose a man who watches porn, I wouldn't have and he isn't going to change.
You also shouldn't be doing all the household chores. If you aren't married I'd leave before I have the baby and get yourself somewhere where there is a bit of a support network as you aren't going to get any from him.

Its fine if you don't want him watching porn that's your boundary (and there are very valid reasons for being anti-porn) but I personally think it's a bit OTT to suggest he never gets aroused by another person ever. I'm in a very happy relationship but I still find other people sexually attractive.

Why are you doing all the cooking and cleaning though? That's the bigger issue imo.

I would not be with a man who watches porn. Many of these women are trafficked, underage and it's non consensual/rape.

Pornhub had to remove masses of content for this reason.

He is disgraceful.