My Mother

Brief history.
I'm the second of four children; my mother (51) married my father in an arranged marriage. My father was 7 years older than her, but they started a family as was required. Having three boys, then finally a girl. After the birth of my sister, my mother got what the doctors called postnatal depression. My father was too busy to worry about his wife's condition and rarely saw her. My older brother (29) is always with my father; I'm too much like my mother, according to my father. He is business-focused, and I (25) prefer some enjoyment to just doing business. My older brother is more like my father; my younger brother (22) and sister (19) are closer to me than my older brother. But they are away at college most of the time. Late last year, my mother seemed to completely recover from her depression. But still preferred to stay on the family estate (53 acres) rather than go anywhere. At Christmas, she suddenly decided she wanted to go horse riding again. I was her chosen riding companion, mainly because I was there. I saddled two horses, and we headed off on the trail around the estate. I followed close behind her on the narrow trail, then she turned off the trail, heading for the log cabin overlooking our 9-acre lake (man-made). I just followed, letting her go wherever she wanted to go. Reaching the cabin, she dismounted and told me to water and tie up the horses. While she went inside the cabin, I joined her in the cabin, and she was undressing. Told me to undress also; I just looked at her. She said she was really horny and wanted me to fuck her, adding that I should help my mother. I wasn't dating at the time and usually did okay, but I'm no chick magnet. To make her happy, I did as she wished. We fucked twice in all and showered together afterwards. Then continued our horse ride; she would tell me she wanted my company, and it always meant she wanted sex. But she started having me accompany her on trips off the estate. Which just meant a new place to fuck, I went with her to a family get-together on her side of the family. A cousin of hers, successful career-wise, was there with her daughter (22), a quiet, timid girl. My mother took an instant interest in her cousin's daughter straight away. My mother started seeing her regularly thereafter. I later found out my mother seduced her. Then my mother talked to her cousin about her daughter. Suggested that we bring the family closer together by having me marry her cousin's daughter. Her cousin was agreeable, and arrangements were set in motion. I was told by my mother that she wanted me to marry her cousin's daughter. She had already gotten my father's approval before telling me. I still didn't have a girlfriend, mainly because I was still getting sex off my mother. I said I would think it over; my mother suggested I join her that afternoon. We went to a cottage close to the college my future wife went to. Met my future wife, and my mother told me we would go into the bedroom and have some fun. At first, I stood naked, watching my mother and my future wife get it on, as they say. Then told to join them, only told no fucking my bride before the wedding. Both sucked my cock, and my mother mounted me and rode till I came inside her. Last month we married, and my wife provides me with sex whenever I want it. My mother also joins us regularly. No precautions are taken with my wife; my mother wants grandchildren. My older brother is yet to marry; neither of my younger siblings is in a hurry to marry either. But I have married and am enjoying married life. My mother calls me her good son.