Sex scenes

Well, as with any phobia (let’s just call it that for the sake of argument) you have to start slow. If people have a strong discomfort towards spiders (arachnophobia) there are sessions of watching pictures of small spiders, until they are comfortable watching those. Then they start watching pictures of bigger spiders, scarier than the ones they felt comfortable watching up to that point. Then just build that up. In your case I suggest watching pictures of people just kissing maybe? :D

I gather that usually people with a dislike of something along the lines of this get taught that at one point in their life. I’m no psychologist but somewhere along the way someone gave you the strong impression that it’s wrong and dirty to watch scenes like that. If you find that instant it might help you give a better understanding of why and maybe even reverse it.

hope it helps :)