I Kissed My Girlfriend's Little Sister♥

"We'd better not let my sis see us like this..." My girlfriend's younger twin sister has somehow become my new stepsister?! "You sound really nervous right now. You're just so adorable, bro." It's been a month since I've started dating Haruka, my first ever girlfriend. We even finally reached first base today—holding hands! "What a bad boyfriend you are. To think you're daydreaming about your little sister while you’re holding hands with your girlfriend, of all people!" Today's also special...