A brother and sister who usually don't get along suddenly become closer through intercrural sex! When the brother sees his sister coming out of the bath naked after work, he inadvertently gets excited by her big tits and gets an instant erection. The frustrated sister has her eyes glued to her big dick and gets horny! She sneaks into her brother's room and rubs her dick against him, but he wakes up! Still, as they continue to intercrural sex, the brother and sister can't stand just rubbing it, so they end up inserting it all the way in and cumming inside! Even though they don't get along, their sexual compatibility is excellent and it develops into intense sex!