The love scenes that worked, regardless of the director, were the ones where the actors weren't fearful. When somebody was fearful, you could see it right away. It takes you out of the story, and that's to be avoided at all costs.
If you come on my property, I've got you from the second that you enter on. There's little lasers... my TVs come on in my room and fall just right on you. So, there's no way to sneak up on me. And I've got a loud dog.