She starts taunting

"Looks like the big boy can't handle his little sister's ass!" Megan says, shaking her booty all over your face. You hear all three girls laughing uncontrollably at how easily your sister is beating you, and how hard you're getting because of it.

Soon enough your sister's ass blocks all your breathing and you start running out of breath. You become more frantic in your attempts to dislodge Megan, but you're too weak at this point to even throw her off.

"Submit to my ass big bro! Admit I'm the winner and maybe I won't make the victory pose too humiliating for you," She says, looking over her shoulder with the biggest grin you've ever seen.