Got invited to a bbq and drinks by a woman i did some work for. It was mid week, Wednesday 6pm. She only lives a few streets away so no need to drive ment i could hook into the free piss and have a good feed. When I arrived there were 2 women in the spa, the lady who invited me and her husband and 2 more of his mates who i assumed were with the women in the spa. The drinks were flowing so i happily helped myself to the beer in the esky and started chatting with the blokes on the deck. About 7 30 the bbq meat was nearly ready and the 2 women in the spa were asked to get out and dress, I watched intently as they exited the spa, completely naked and wrapped a towel around themselves. Their van was parked in the drive near the side gate and it was obviously their wardrobe as they started heading for the gate. One of them asked if I could escort them to the driveway and wait while they changed, i grabbed another beer and followed them through the gate. Turns out they were the sisters of the woman who invited me and not at all involved with the husband's friends. When we got to their van the slightly drunk sister asked if I was gay to which I replied, no, why. She said because I'd not commented on their naked bodies and I explained that I consider myself as ugly as a hat full of busted assholes and there wasn't any point in me complementing 2 attractive ladies in their 50s because they would have no interest in me. The sober sister was in the van changing while i chatted with the other, then they switched and I chatted with the other while her sister got changed. We returned and continued eating, drinking and chatting. About 11pm it was winding up and the drunk sister asked if I wanted a lift home which I gladly accepted even though it wasn't far. When they pulled into my driveway the drunk sister said they were only interested in what was in my pants, not how I looked and could they see. Sure i said so we got out and I released my cock, they both had a feel and it started growing, the drunken sister said i think this can be yours, it's a little small for me. I wasn't sure what she meant but it seems if it's a big cock the sober sister sucks and the drunk sister fucks and vice versa. I was well pissed and thought I'd won the lottery when she started sucking my cock, it was hard in no time and the sober sister opened the side door of the van and lent in, positioning her ass in the doggy form and lifting her dress. The sucking sister then positioned my cock head at the opening of her sister's cunt and told her sister to push onto it, once i was in i started pumping away and didn't last long, filling her cunt with my seed, i pulled my cock out and the other sister sucked me clean then rubbed her sister's cunt and licked her fingers. Having finished they thanked me and asked if they could come around again sometime, sure i said , we said goodbye and i went inside thinking what the fuck was going on, best bbq for a long time.