Whoops, long-ass post. So, I'll mostly be talking from a place of personal experience here. I was molested multiple times as a child, one was incest. Now, this proceeded to fuck up the way I viewed sexuality and I got involved with the BDSM community at the age of 16. Like. I found local dudes twice my age and entered shitty relationships sorta BDSM. I honestly can't even remember being "conscious" of my actions, in the philosophical way, until I was 20 or so. Because, when you are molested, it has this nasty habit of hobbling your emotional growth as a person, Misery-style. That sucked ass. But I digress. Don't be like me, kids.
Chances are, if you are anything even remotely like me, you have a predisposal for re-living your abuse in a way that makes you feel like you're in control. And you think that's hot. Yeah, I know the feeling. There's a reason why so many kinksters were spanked as children.
You are an adult. Your SO is an adult. You can bring up the fantasy, and then explore it as consenting adults. You can explain that this is something that makes you feel good and comforts you, if it is. That is okay. I deleted my learned incest kink years ago but struggle-sex still rustles me up good, and it probably always will.
Unless he's uncharacteristically moralistic about therapy and coping strategies, he's almost certainly not going to be disgusted by you. If anything, he'll be sympathetic. He might pity you at worst. I'm not going to argue the ethics of it, or whatever.
You have to ask yourself if you want to accept it, and how much it really bothers you. If you knew that your ex would unconditionally accept this part of your history along with your kink, would you be bothered by this? If you don't feel conflicted by this, then it's your kink and do with it as you will. Own it.
If this makes you uneasy, then you still have some issues to work through. I tried to fill my own gaps with kink and clingy, near-codependent relationships. I fed my unhealthy ideal of romance. I was almost diagnosed with BPD, but I made drastic changes to my life at the last moment and now I'm okay.
The TL;DR is that I'm no longer all that kinky. I still love giving BJs (A LOT OF BJS) and play-fuckfighting, but that's all normie stuff at this point. The point is, I abstained from polishing my gimpsuit for three years and now I barely get the urge to indulge in the stuff that reminds me of my terrible childhood, and I'm happier for it. Made serious progress with my mental health this year. This worked for me, but it might not work for you. You do what works for your lifestyle and the kind of person you want to be.