When I went into the kitchen, my daughter had her blouse open and was feeding her baby, one plump breast visible through the open flap of a white nursing bra. I apologised and turned to go but she said it's okay dad, you can stay. I sat down at the table to watch. Her little girl suckled contentedly at my daughter's nipple until Mary wriggled and said this bra is really uncomfortable. She gave the baby to me to hold, shrugged away the blouse and took the bra right off. She arched her back so that her breasts jutted. That's much better, she said. Her pretty, milk-swollen breasts that I had always lusted to see and touch were now completely nude. They were as beautuful as I had imagined. She took the baby back and slipped a nipple back in its eager mouth. Beads of milk glistened on her free nipple and she wiped them teasingly away with her hand, knowing I was watching intently. She fed for a bit as if I wasn't there, staring at her baby, and then said quietly do you remember when you used to watch mom feeding me? Of course I remembered, perfectly, and I wondered how much Mary knew. It turned out that she knew everything. Mom told me you used to sit and masturbate yourself while you watched us, she said. Is that true? I nodded guiltily, aware that the bulge in my trousers was both uncomfortable and obvious. Mary looked at me steadily. Would you like to masturbate now, dad, here in front of me? It's safe. Jim won't be home for hours. Honey, I said, and realised my voice was thick with excitement and embarrassment. Dare to do it for me, dad, Mary said in an encouraging tone. I want to know what you looked like when you watched mom and me. I slowly undid my trousers, pulled out my cock and started to fondle the head as I like to do. Wait, she said. Put a towel on the floor for when you cum. I obeyed and resumed playing with myself under Mary's gaze. Easy does it, dad she said. There's no hurry. We both want to enjoy this. Just tell me what to do, darling, I said. I'll do whatever you want. I masturbated slowly with my pants down at my knees so that she could see everything. I wanted to be totally exposed for her. I could see that watching me wank while the baby suckled and pawed at her bare breasts excited her. She rolled her head gently with her eyes half shut and breathed heavily. I wondered for a minute if she realised I was still there until with a sigh she said you can go, dad. Her body heaved in her chair as I simultaneously shot a huge load, managing to miss the towel with most if it. We sat not speaking for a bit while we recovered our calm and then I watched as she put the baby down and put her bra and blouse back on. She nodded at the cum I'd splashed on the floor. Clean up your mess, dad, she ordered? I was scared she was angry now but when I'd done wiping up and fixed my clothes, she gave me a peck on the cheek. You dirty old bastard, she said. I can see why mom let you do that? I was a dirty young bastard then, I objected. And she didn't let me. She made me - like you. Mary laughed.