Casey's Sister

Casey didn't waist a moment, the next day I was being flooded with messages from her about her stuck up little step sister who she couldn't stand.

The picture didn't give very much of a hint other than she was another cute and petite thing.
Not long after Casey sent the messages, another one came in to my surprise.
"Hey! This is Sophie! I hate to just message myself! But my sister said you might be able to help me earn a buck doing my favorite thing! Modeling ;)"

(From here will be two paths, one a more vanilla path, the other a more hard-core bdsm/submission type. Please message for kinks and suggestions!)