My exwife was a horse and pony person, more of a hobby , than a serious rider, but we had a lot of tac and a nice barn. After she mentioned an interest in pony play, I fashioned her a bridle out of nylon, a lead shank, and made her a tail out of a but plug ,wire and a couple of costume wigs . We played a little at horse training, all kinda ok. As a surprise I arranged for another couple to join us in the barn. I led Doris by the bridle into a stall and tied off her lead shank to an eyelet , to keep her from moving too much, she was on hands and knees, tail in the air, on straw. She was puzzled as to what I was up to, At that point Kathy led Tom in, on hands and knees, until his face was right behind My exwifes bottom. Time to breed the Mare! The stallion is required to tease the mare in to breeding, sometimes a "Teaser" is used, an older stallion, not in a rush, to excite the mare orally . As I didn't have time to arrange another teaser, we went with what we had and Tom did a more than adequate job. I held her tail, up and out of the way as Kathy guided Tom up onto Doris. with one thrust he was all the way in her. He plowed into her repeatedly, just like a rampant stallion, until he filled her with semen. Doris's eyes were wide with shock , as this was the first time that Tom had entered her without a condom, but 8 weeks prior he had had a vasectomy, which tests proved to have been sucsessful. Tom pulled out ,and he and Kathy went up to the house to clean up, leaving my ex and I in the barn. I untied the leadshank, removed her tail and bridle. Her face was flushed, and a little confused. She said it was the most intense moment that she had had sexually. Doris laid down in the hay and opened her legs.