Holiday with family part 1

My name is Dan and my wifes name is Bec. We have been married for about 28yrs, with 2 kids - one boy and one girl. Both are grown up and have left home so Bec and i are home by ourselves. Our sex life is ok and we can do it anywhere in the house we like
Bec has a sister - Kelly and her husband is Ryan. Bec and her sister are very close and they come over quite often for dinner or a swim. Bec has words with me when they come for a swim because i check Kelly out because she wears a brief swimsuit. You can see her nipples sticking out and her pussy when she gets out of the pool.
Bec and i had been working long hours for the last month so we decided to have a break for a weekend up the coast. I made arrangements at a hotel that was near the beach. Kelly came over one arvo and was chatting about where we were going and when. All of a sudden Kelly asked if she and Ryan could come as they needed a break as well. Bec told her it would be find and be able to have some fun. When Bec told me i was not real happy.
The day came we were getting away and we left on the Friday just after lunch. Kelly and Ryan came in there car and we in ours. We booked in and i told Bec we might go for a walk along the beach and a swim. Kelly heard and asked if she could join us but Ryan was going to have a sleep as he started work early this morning. Kelly and Ryan had there own room, which had a joining door between our room. We got changed and off we went for our walk. As we got to the end of the beach i saw a track that led to the other side of the point. As we started i noticed a sign that said - NEXT BEACH CLOTHING OPTIONAL. I showed Bec and she asked if i wanted to go and i said why not. I saw her pull her legs together and she asked Kelly. She said she had never been to one but would like to go. We got most of the way round and we stopped for a rest. As we took in the view Kelly asked if we had been to a beach like we were going to. Bec said we had been to one but what about her. She hesitated a bit and then said no, but she had thought about it but Ryan did not like them. We continued on our walk and was not long before we got to the beach. Not a lot of people but some in swimmers and quiet a few naked. I told Bec we might walk up near the end so i let the girls walk in front. This way i could check all the naked women. We found a quite area next to an elderly couple, put the blanket out and settled down. I asked Bec if she was going for a swim and she said she was. I then asked the girls if they were going naked or swimmers. Kelly asked me what i was going to do. I looked at Bec and i told her naked. Bec said she was going naked. We both stripped off and Bec then asked Kelly what she was going to do. After a bit she stood up and took her swimmers off. She had nice tits, big nipples and a shaved pussy. We walked down the beach and got into the water. Bec as usual was horny and cuddled me while Kelly kept close. Bec told us she was horny and when we get back to our room to watch out. Kelly told us she was feeling the same and was so turned on. Bec got Kelly to come over to us and cuddled both of us. I felt a hand on my cock and i thought it was Bec but it was Kelly. Bec stopped cuddling me and pushed Kelly onto me and told me to give her a cuddle. I did and felt Kelly rap her legs around me. I then felt my cock slip into her pussy. Bec was behind me and she whispered in my ear - FUCK HER SHE WANTS YOU. i looked at her and she asked me to fuck her - it was ok with Bec. It felt so good and was not long before both of us cum. We settled down and went back to our blanket. We chatted for a while as to what happened and Bec told me they had talked about what had happened and she was ok with it. The couple that was next to us had left so we had the area to ourselves. Thy were both on either side of me so i took a chance and put my hands on there pussy's. I turned around so my cock was up near there faces. I continued to finger both of the and they were getting turned on. I felt there hands on my cock and balls. I had 3 fingers in each pussy and played with there clit with my thumbs and both were moving and they both said they were going to cum. All of a sudden i felt a mouth on my cock and it was Kelly. When they were going to cum i was as well. They both put a hand on mine and pulled it into there pussy. I felt the mouth swollow all my cock and i let go - i cum and i looked up and it was Kelly. After we settled down we got dressed and went back to the hotel. We all agreed not to say anything. Kelly kissed me - with tongue. Bec kissed her and we went to our own rooms.