Your step-sister is so much smaller than you... at first. She was such a baby! You laugh at her, poke fun at her. She whines about it...

After some time in college though, she comes back a lot bigger than you. She's picking on you now, SO much more than you ever did. You wish you'd never done it now. She shows off how tight her bikini is now - a "normal" size doesn't even fit around her massive body. You could never compete.

You were just average tall. She is an Amazon Goddess.