This happened a couple of years ago and just had to share it with all of you, I still get hard over it today and hope it happens again.
I was at a local beach wearing a pair of shorts lying on my towel. A couple of metres away were a group (three) of girls that were wearing very cute bikinis. I couldn't keep my eyes off them as they were rubbing suntan lotion on each other. My dick was getting very hard just watching them, I tried to hide my excitement but what ever I did was making the situation worse (especially since I didn't want to turn on my stomach cause then it was turn hard to watch, plus my dick was too hard by this stage). I decided to stay as I was and hope no one noticed, 'fortunately' I was caught by one of the girls and she told her friends. They all turned to watch me or should I say my dick. I thought I was in trouble, but lucky for me they liked what they saw and shouted out that they wanted to see more.
All three of them came over to sat next to me, I couldn't believe my luck, they sat crossed legs in front of me and asked if I could remove my shorts to get a better look, as there wasn't many people around I did what I was asked and out sprung my hard dick for them. They each took turns rubbing it and laughing, I couldn't control myself it felt so good. After about 5 or 6 minutes I asked them if they would show me more, they agreed to take their tops off but wanted to keep their bottoms on. I didn't care because there boobs were so good it had me even harder. I took over from them and jerked my dick for them to watch, I could see them getting horny, cause one of was biting her lips watching me. Then I saw one of them with her fingers in her pants rubbing her pussy. That was it, this pushed me over the edge and I cummed so hard it went everywhere, all over my body. This pushed the girl jilling herself over the edge as well and I heard her moan. They then put there tops back on and went back to their towels. I was spent and just laid there with nothing on for a while. As I got dressed and left they said to me we should do it again some time - we have gotten together again but this time they got fully undressed for me, but that's another story.