So me and my gf of a few years are off to a music festival abroad. We are both in our late 20’s. She is slim, tall, Asian/white, small breasted, well heeled girl. She was quite wild and had a naughty side with a bit of a slutty past. The type of girl that was well dressed but never wore panties anywhere, and was a flirt. We always had great sex and I would enjoy licking her till she squirted and she gave good head. I am 7/8 inches so not too bad. We both appreciated when we saw a hot girl or guy. We are on holiday now and been out the night before, there’s 3 athletic black guys staying one apartment down that have been friendly. In the morning I said I will run down and get some bottled water, she said she’s going to say hi to our neighbours, dressed only in a bikini. Cool I will be straight back. To be fair our relationship was quite open but we haven’t done anything. Her friends did always hint to me that she was quite a slut. On my way walking down the balcony back to ours with the water. I pass the guys apartment, with the door wide open to see my gf on her knees blowing a huge black cock. He was at least 9 inches, she was fitting as much as she could in her and wanking him. The other two guys patiently waiting for their turn. I was shocked but quite turned on quietly watching her give amazing head. It didn’t take long for the guy to cum over her face and the next one took his position. I then walked away into our apartment before I was seen. A few minutes later my gf walked in smiling with a face full of cum. It secretly turned me on knowing what happen and her looking like a slut. I asked her if she had fucked them, she said no. So I undone her bikini bottoms and pushed her on the sofa and began pounding her.