My husband and I have always had a very active sex life. He has badgered me to consider swapping but I didn't think it was something I wanted to do. I'm 35, slim, my husband says I have impressive 'tits' as he call them and to be honest I am quite proud of the fact they are still form after having twins a 18 months ago. I go to the gym 3 or 4 times a week so keep my figure in check. My husband's fantasy is to see me in bed with a total stranger which I think is a bit odd for a husband to want to see. Anyway onto my story. We went on holiday to South Africa with a couple who we have known for some time, Tim is an old friend of my husbands and is absolutely gorgeous, he's 6' + and a hunk of a guy, is wife is tall and very attractive. We all get on very well and play tricks on each other regularly. However, during the holiday I was becoming suspicious that my husband was having an affair when I kept catching him texting someone, for a while I thought it was Tim's wife so I decided to pinch his phone to read the texts. It turns out my husband and Tim where planning to play a trick on me. From what I could see they where going to say that Tims shower wasn't working in their room and wait until I was having a shower. Then my husband would make an excuse to go out and Tim would come in, get undressed and walk into the shower room pretending to be embarrassed but just stand there trying to explain the error and see how long it would take me to freak out. Personally I thought this was going too far but decided to play along. I would just stay there and listen to what he had to say and then cover myself in soap and give him a show pretending I wasn't bothered that he had come in to see how long he could take it. The day arrived and I was in the shower and sure enough Tim walks in completely naked. He pretends to freak and apologise, stuttering and pretend to get all embarrassed. I opened the shower cubicle and stood there baring all and listened to him go on. I told him not to worry that mistakes happen but he went on and on. So I got the sponge, covered in soap and started to lather myself making sure I paid attention to my boobs. The idea being that Tim would get embarrassed and walk out but he stood there staring at me and talking crap. After a little while he started to get a hard on and his cock got bigger and bigger. I found myself staring at it and realised I was rubbing the sponge between my legs. When I realised what I was doing I went back into the shower thinking he would leave but instead he stood at the cubicle door for a few seconds before joining me. Neither of us said anything for a while but I couldn't resist taking his thick hard cock in my hand and gently pleasure him. I could hardly get my hand round it becouse it was so thick. Within seconds of me starting this I was tossing him off and he was exploring my breasts, squeezing my nipples with one hand and putting his fingers deep into my pussy with the other. I had my first orgasm at the thought of how naughty this was and my knees gave way a little. I started to stand but Tim put his hands on my shoulders and pushed me to my knees. My mouth strained to get round his shaft but in the end his cock was touching the back of my throat causing me to gag. He continued to fuck my mouth and I could feel the trickle of his pre cum on my tongue. Before long he pulled me up, put his hands under my backside and lifted me up impaling me on his shaft and we fucked. Even now the memory of the warm water on my breasts with Tim's tongue deep in my mouth and his cock stretching my pussy lips as he thrust himself as deep as he could inside me and his hand squeezing my solid nipples makes me quiver. We fucked for so long that in the end I had to ask him to cum inside me before my husband came back. Tim obliged filling me with warm sticky cum. This was too much and I had the deepest orgasm of my life, so much so I had to sit on the shower floor to get myself together as Tim dried himself and dressed and with a quick kiss he was gone. I massaged my breasts and came again before getting dressed. No one said anything about it and nothing else happened between Tim and I. Do I feel guilty ? A little bit but my husband set it up so he should have known what may happen.