You kick first

“Fine. You wanna go first? Be my guest,” she tells you as she spreads her legs as far as they’ll go.

Now that you’re confident that you’re controlling the outcome of this game, you kick your sister as hard as you can between her legs and she lets out a yell of pain.

“OOOWWWWW!!! Oh my God! That fucking hurts you stupid dick!” Kathy screams in pain. “You’re gonna pay for that,” she says. “Spread those legs, asshole,” she demands, in much less pain than you had hoped.