Husband not respecting boundaries

My husband and I have been together 6 years. There’s something I’m not okay with. Its small, maybe stupid. It’s when he goes down and kisses my butt when I have no pants on. I have PTSD because of rape.

We’ve had this conversation about what’s not okay and I’ve explained why it’s not okay. It triggers flashbacks, it makes me panic..

But for 6 years, he keeps doing it. Not daily, but still often. I always told him to stop and explained it again. He always stopped when I asked but would do it again at some point. We haven’t been having sex in probably 6 months, we’ve been going through some things. And recently decided we wanted to work on things.

Today, I decided to tease him a bit and the first thing he does it put his face right there, kissing and biting my butt from behind. I immediately started crying. I want to like it. I want to enjoy it. But it fucking makes me remember too much.. it triggers too much. He stopped. But now we are having a huge fight because he keeps saying it’s no big deal because he stopped and he forgot that he couldn’t do that.

I’m upset, crying, having a panic attack and he’s yelling at me telling me I’m “fucking unbelievable” because i said it wasn’t okay because I’ve been telling him for years and he still can’t remember.

He says it’s my fault he can’t remember because we haven’t been having sex for he forgot what the boundaries are.

He said he “forgot” because he’s been depressed lately.

Am I in the wrong here?...