"She's a difficult pleasure," I said of my ex-wife. I was standing at the front door of her house, talking to her new partner, Sammy, a woman. My ex-wife, Lily, was not there. We both took in the complex and awkward implications of my statement before Sammy smiled, her illusive lesbian I've-experienced-more-than-you'll-ever-know-and-I-don't-need-to-prove-it-to-you smile.  I smiled back with a polite, You're-probably-right smile.  Then her lips curled up into something genuinely happy—I guessed she was remembering a moment with Lily or connecting some dots into a picture that pleased her. I