During our summer holiday, in the south of France this year Lucy was more frisky than usual. The first two days had been much as usual, more frequent sex than at home, a shag each night but then she changed wanting to go back to the mobile home and fuck during the day, before we went out at night and again when we got back. I wasn’t complaining, but puzzled by her sudden change. The next day after an afternoon fuck she wanted to go to the local town and went shopping while I waited at a café. Being France she went topless on the beach, just wearing bikini pants, when we got back she went in the shower then the bedroom to change. About 30 minutes later she came out of the mobile home a sarong tied just above her tits and we headed for the beach. As soon as we reached the beach she removed the sarong, putting it in her bag. Just wearing a thong I hadn't seen before, tits naked, swaying as she walked, her bum uncovered. Lucy is almost forty, her 36d tits whilst not quite as firm as they once were, certainly haven't sagged. She is slim, has a lovely rounded bum, great legs and for the holiday had her hair cut short. There were other women wearing thongs it was just a surprise to see her in one. We headed down the beach, me admiring her almost naked body, pleased that I wasn't the only man looking. I asked her about the change in her, wearing the thong, bonking three times in a day. She gave a cheeky smile saying she'd tell me in a minute. Stopping near the boundary with the clothes optional area, a few people sun bathing naked about a hundred yards away, two men near to us in beachwear. I laid out our towels as Lucy rummaged in her bag, then standing in full view, facing the men, took off the thong, revealing that since the morning she'd shaved her pussy. She dropped the thong in her bag, picking up a replacement and put it on. It was just a tiny scrap of material, a narrow tear drop, no more than an inch at its widest, sheer, unlined, her gash visible. Standing above me she turned round, all that held it was narrow string over her hips and between her legs. “Like it? It's the smallest string I could find”. My hard cock stretching my trunks was her answer. Instead of laying down she went down to the sea deliberately passing close to the two blokes, then wading up to her waist in the sea. Walking back she stopped to speak to the men standing, with them looking up at her cunt. As she got close to me the wet material was see thru, the cloth pulled tight in her gash, her large fleshy pussy lips hanging either side. She may as well have been naked, although this was much hornier than being nude. She got down beside me and I asked what she was up to, flashing her pussy to two blokes. She explained, reminding me how I’d had a bit to much to drinks a couple of nights before and she'd gone out for a walk about 1030pm. She'd walked along the beach and heard people and could see some light from the dunes, getting closer she could see the light from gas lanterns, and men and women fucking. She watched and a man had come over to her, inviting her to move closer. There were more men than women and she'd watched as one woman had been fucked by several different men, her own pussy getting wet at the sight. The man next to her had been stroking his erect prick and had his other hand on her bum, pulling the back of her dress up. She was so turned on watching the woman being fucked, and didn't stop him when he pulled her dress over her head and pulled her panties off. She'd turned on her side facing me, stroking my hard on, her face close to mine. I asked “Did he fuck you?” “No” she replied, “I wanted him to, and almost let him, especially when he got down and started licking my pussy. But I was thinking about when we'd talked about another man having sex with me. How hard your cock gets and I wanted you to be there to see me being fucked and didn't let him”. She had let him finger fuck her and tossed him off, and she had climaxed on his fingers. Before leaving he had asked her to go again and told her to come to this part of the beach this afternoon. “I want us both to go, we've talked about it, we might never get another chance, I bought this string just to see if I had the nerve to wear it, to see the reaction. Did you see those two over there, they wanted to fuck me, just the thought got my pussy tingling”. She'd got my cock out between us and was still stroking me. I was excited thinking about her taking another mans prick as she wanked my cock until I could hold back no longer and shot my load all over her stomach. “I take it that's a yes then” she laughed. She got up and said “I'll go and tell them we'll be there” and walked over to the two blokes she'd spoken to earlier. Crouching next to them she did the sluttiest thing I'd ever seen her do, (at least until later that night). My spunk was running down her and as they watched she massaged it into her skin. Checking no one else was close enough to see, she pulled the strip of material to one side, exposing her cunt and masturbated in front of them, even letting them push their fingers inside her hole as she wanked until she came. She was really pleased when she came back over that she'd had the nerve to do it on a public beach and had proved to herself that she would have no problem having sex with, and being watched by, complete strangers. However if I thought she'd been a slut it was nothing compared to her behaviour that night.