I thought the board would be closed today.
But, anyway, maybe those 'weird sexual moments' stand out, because he doesn't do it all the time. It's in his stories now and then, so it's not like with Clive Barker where it's a standard ingredient. So every time he puts it in, it feels a little odd.
But I can't shake the feeling that he's been more strongly sexual in his writing in later years. I assume Gerald's Game was his first overly sexual themed novel, so it was clearly a subject he felt comfortable with and wanted to use it more often.
The feeling remains for me, that like that other person said, it doesn't add a lot to the story often, or sometimes the use of it I find confusing, like the True Knot watching porn movies to disturb Abra - that's just such an odd concept to me. And clearly it was left out of the movie too. I'm not sure if Flanagan wanted to use it or not (I feel in his adaptation he took out many elements, but also put a few new ones in), but it would probably never pass censorship.