My wife Helen and I were out to a fancy dress party on Saturday night and it turned out to be the best ever. Helen is 5'2", blonde, size 12 with lovely firm boobs and a great arse. As with many couples, we've spoken about sex with other people, but never got round to it. Helen decided to buy a elephant onesy and I dressed as zorro. We arrived at the party and were surprised at the size of the house, it was huge and at the number of people that were there. There must have been at least 12 women there dressed in elephant onesies. Everyone had been given full face and head masks, which made it impossible to tell who was who. We were given our drinks and started to mingle and as the evening wore on, we were getting more and more tipsy. I took Helen up for a slow dance and she whispered in my ear that she was feeling really horny and thought that we should have a bit of fun. We had noticed how couples had been drifting off upstairs, but because of the large number of people there was still lots left dancing, drinking and chatting. Helen suggested that we should split up and then I should try to find her amongst all the elephants in the room. We split up and I tried to keep my eye on where she was going but lost her in the crowd. I started to chat to a lady dressed as a french maid and went up for a slow dance together. We were immediately kissing and as we were I was scanning the room to see if Helen was watching, but it was like looking for a needle in a haystack. I was rising to the occasion and my new partner took my hand and we went upstairs. To my surprise we passed a room where at least 10 women dressed in elephant onesies were queueing up. My new partner told me that this happened every year and they were queueing to have the stitching undone from their crotch, so they could have sex without having to take of their onesy. I wondered if Helen was one of them and if she was, what was she going to get up to. My new partner and I found an empty bedroom and within minutes were on the bed naked. She had a fantastic body, with a lovely juicy pussy which tasted divine. We were very quickly into a 69 and she came very quickly, then jumped on top of me, pushed my cock into he love hole and rode me like mad. It was a fabulous experience, as I had been totally loyal to Helen and another woman fucking me was out of this world. Another couple came into the room, the woman in an elephant onesy and the man in zebra one. He had his cock hanging out of it and she obviously had the stitching removed from here crotch, when he thrust straight into her. I couldn't help but wonder if it was Helen, but here were no telltale sounds. We went back downstairs and found ourselves new partners. This time I was dancing with an elephant and again wondered if it was Helen. She was the right height and her bottom felt right as I carressed it. I took her hand and led her upstairs, where she stripped my off and I was hopeful that I would be able to remove the onsy, but she got on top of me and pushed my cock into her soaking pussy. No words or sounds were uttered and despite fucking for 5 minutes, I couldn't tell if it was Helen or not. She rolled of and I immediately went down on her and started licking her cum filled hole. Another 2 guys had coem into the bedroom and they beckoned me to step aside, which I did, thinking that if this was Helen she was going to get a really good fucking from these 2 young guys. I watched for a few minutes and then went back downstairs. Once again I was dancing with an elephant and it was a repeat of my first elephant fuck, and I still couldn't tell if it was Helen. Towards the end of the evening the floor cleared and the host called for a volunteer to take on some of the men present. An elephant came forward and she was bent over a chair ready to take on her first man. The host then asked for volunteer men to come forward to fuck the elephant. Was this Helen I asked myself. 8 men came forward all of which had their cocks in hand and some were enormous. The big ones waited till the end. The elephant took one every single one and received rousing applause at the end. The evening came to an end shortly after with evryone getting back together with their own partners. Fortunately Helen came to me, because there was no way I would have known which one she was. The first thing I did notice was that she had her stitching cut and was damp down below. When we got into the car, she said it was now my turn and that she had leaned a lot that evening and wanted to do it again. I didn't find out if I'd already fucked her with the 2 young guys or if she was the volunteer elephant, but who's worried, she enjoyed herself and so did I.