I think a lot of people are missing the point.
It’s not about whether what he did is ok, it’s that it’s not OK for OP, she’s communicated that to him and he’s done it anyway and then lied.
OP also explained it’s not the wank that’s the issue, it’s watching porn next to her.
If DH did that to me, I wouldn’t mind. We are open with each other sexually and in fact I would probably help him finish. But if it was something I’m uncomfortable with, and he knows it, then it’s really disrespectful.
A similar analogy is farting. I think it’s rude and disrespectful to fart in front of others, even at home. That’s how I was raised. When we first moved in DH would fart in from of me and I hated it. I found it really off putting and unattractive. It took him a while but when I explained that I don’t like and I find it disrespectful, he stopped. I hear him fart when he’s in another room and that’s fine - as long as it’s not in front of me.
That’s not controlling behaviour. It’s having boundaries in a relationship which both individuals sign up to, and respect. For OP he crossed a line in their relationship. Just because it’s not a line in my relationship or for others, doesn’t mean we can downplay OP’s hurt.