Grant after spending the weekend sampling the carnal delights of young Tess returns her home to her mum Tanya. He finds her aunt Ronnie there too, and finishes up taking her aunt to his apartment for a sleep-over (not much sleep tho). They are joined in the morning by Tanya for what develops into a sensual threesome.
His PITA of a sister was in charge while their parents were away, she teased and pushed him around until he was not going to take any more. Only his revenge did not quite go the way he had planned it.
Josh, while taking a break from his stocks and securities activities, encountered a troubled woman in Hawaii. He wound up in the middle of a debacle, between a sibling rivalry and an Adonis, but wound up making the trade of his life. The sisters/lesbian tag comes to light very, very late in the story and is not a prominent theme.