With her younger sister

Professor Snead's younger sister, Natalie Snead, was currently living with her, due to some financial difficulties. However, they often had fights due to Margaret's views, which Natalie disagreed with often. She sometimes just wore skimpy clothing to piss her older sister off, who responded by selling parts of her wardrobe off and cutting her money sources.

One morning after a fight they had resolved with some difficulty, Natalie got a strange urge. It related to a dream she had, where she drugged her sister with some drinks, and had gotten her revenge on her for being so annoying all these years. She spent the rest of the day on her computer, investigating aphrodisiacs and related drugs that could turn her prude older sister into a slut.

After some hours of looking, she found her answer. A drug that would last for at least a week, and make her sister rather slutty. It required a minimum amount of dabbling into the deep web, but it was rather simple.

The name of the drug was Benedarone Exustin, and finding in the online market wasn't hard at all when one knew where to find it. A few clicks, and she had a delivery guaranteed to arrive before the end of the day for just $1000 dollars, a small amount from the amount Margaret gave her, plus her savings.

A few hours later, before Margaret got home from college, Natalie received her package, containing a few small bottle of the odorless, tasteless substance, which would easily blend with water or juices. With her tools, she got to work, making her sister some of her favorite juice, rhubarb, which she found odd, and once she was done, added the substance, and waited for her sister to return.