I fuck my 18-year-old stepdaughter whenever my wife is on her period

Anytime my wife is on her period, my 18-year-old stepdaughter steps in and takes care of my sexual needs. Just as I was about to go into the shower, I entered my stepdaughter's bedroom and made her suck my cock. Later that day, I ate and fucked my stepdaughter's pussy in the dining after she got back from school.