Should They or Shouldn't They?

 I notice I always reach the same dilemma in most of my stories. When should the characters get it on? It's inevitable that at some point in the story they will. After all I write adult paranormals. No, not erotic paranormal romance (though some of my friends would argue that point) but the bedroom door stays wide open. But when do the characters hit the sheets?
Sex scenes are not easy for me to write. But if the timing is off, they're impossible. There's a little voice going off in the b...