Sister in law part 3 so after her bath Karin came to dinner in one of my wifes bathrobes over dinner she asked me if it was always that much fun and enjoyable? Kind of ya that is why people do it all the time all over the world.. I complomented her on her new look hair two eyebrows her smooth soft thighs she blushed a little said thank you. She then asked if all guys are the same took me a bit she was asking about cock size . I said oh no just like everything some are bigger some smaller some wider you get it just like women and boobs they are all different. She then mused about trying another but who. I said that is what dating is for. But I said Pat and I used to swap with friends of ours. She did not understand swap so I had to explain that we would have sex with this other couple in the same room the idea of that seemed to excite her. I said I will see it they are around. I called Chuck and Cat they had met Karin in the past and knew her to be a pitch. I explained what was going on and told Chuck all doors are open nearly a virgin he was all in. Cat was looking to play as well. We finished diner and I took her to my bedroom opened the closet and told her to pick something nice from my wifes lingerie she then asked how it is that I can just make my dick hard at will. She really did not get anything at all about sex or human interaction. I then explained that it was kind of her job to excite her partner How you look how you act what you do all play a part. I said that is why you look good and smell good she said ok I guess. I said do you understand what foreplay is? She said no. I said kissing touching does that arouse you she said yes. I said the guys as well. Do you like looking at my cock. YES she said. Do you like touching my cock? YES she said. Well maybe you should suck my cock? She looked puzzled. Remember just a little while ago when I put my mouth on your pussy yes? Did you like that? YES. Well you can do the same to your partner he will like that very much. She did not say a word just reached he hand to my cock and pulled down my shorts I was still semi soft and she bent over and licked my dick really not knowing what to do I coached her to touch my balls lick my balls shaft and head Just explore do what you think would feel good. This went on for about 5 plus minutes I was now hard then I had to take her head and guide my cock into her mouth gently I explained not to bite use your tongue then I had to kind of bob her head up and down and mouth fuck her she really did not get it. After a bit she seemed to understand an got into a groove. Se did OK kind of like your first blow job from your 16 year old girlfriend. I told her I was going to cum and blew a small load in her mouth she was supprised but swallowed it all like a champ. She said I thought there would be more. Again I had to explain how balls work and that I already came in her so the next one is not so big. She said she liked that. About and hour later a knock at the door It was Chuck and Cat they looked great I welcomed them in at greeted me with a full mouth kiss I introduced them to Karin the said Hi and Cat went to her and kissed her full on the mouth and ran her hands down her body. Chuck and I hugged and Chuck went over and gave Karin a kiss and an ass fondle. It had been a while they looked great after a couple of glassed of wine Cat took my hand an led me to the bedroom Chuck and Karin were right behind Fairly quickly clothes were on the floor Chuck is a little shorter that me but his cock is big and fat Cat was sucking me and Karin was trying to do whatever Cat did she was having a tough time trying to swallow Chucks cock. Cat leaned over kissed her and said don't sweat it just do what you can do. I got on top of Cat and we started to fuck she reached out and held Karin's hand as I pushed in and out Chuck then got up turned Karin over so she was on her knee's and slide in with him saying Fuck that is tight I did not take long for his giant cock and her barley used pussy to cum He was disappointed to say the least I was not far behind him and let out a sigh as I came in Cat she without missing a beat went straight to clean up Karin's creampie she started to lick her Karin is moaning not knowing what to do. Chuck wispered in her ear just enjoy. After a bit Karen let out a moan and she came again. Chuck and I were hard again massaging each others cock while we watched the girls Chuck laid down I got Karin on top of him bent her over so I could enter her ass Ya I know Chuck and I are now rubbing out Cocks together but what fun Karin seemed to really like that. Cat was just playing with Karin's tits as he did out thing. The night ended with Chuck and Cat sleeping over in my bed with me and Karin shower for 4 in the morning Kind of a fun night.