There's something about that time just before you kiss. Just before your hands touch. There is this dwindling space between you and the object of your desire. Your bodies lean in with expectation and passion. I love that prelude. All the lust is bound up in those leading moments. In the scene below from Bright Star, there is an actual wall between John Keats and Fanny Brawne, but the barrier only enhances the fervency of their affection in my mind.