step-sister was in a video call with one of her friends. She goes to the kitchen and catches her step-brother fucking a bottom half of a sex doll, and using virtual reality glasses. She shows to her friend what he was doing, asking what she should do. Her friend tells her to swap the sex doll and put her real pussy. She hangs out the phone and lubricates her pussy with the lubricant on the table. When he leaves the sex doll to lubricate his penis, she swaps the doll for her pussy. He fucks her until he comes inside her. He never noticed the different, and he will never know.