I know that every actor that I know, when Daniel Day-Lewis does a film, and he doesn't work that often, but we run to the theater to see what he's up to, and with such delicious excitement. The same goes for Meryl Streep.
I've done sexual stuff before - onstage, which is even more emotionally difficult. With a TV crew around, you are stopping and starting; it becomes really technical. It's not erotic at all.