Riley is hanging out in bed on her phone when her stepsister Dakota Marr comes in with a really naughty idea. Hands behind her back with a surprise, Dakota tells Riley about a new viral trend, the Fuck My Stepsister Challenge. Upon explaining, she pulls a strap-on out from behind her back and shocks Riley. With little convincing and a lot of pent up sexual interest in each other, they give in and have a lot more sexy fun than they could have ever imagined.
