Visit your younger sister, Tina

You think you had enough with your mother, so you decide to try something out with your 18-year old sister, Tina. You turn yourself into the red goo and you slither through your house, going to Tina's room. Upon entering her room, you see Tina browsing through her smartphone while lying down on her couch. She was wearing a colorful sleeveless dress, which went nicely with her brunette hair. You think that since she's distracted, it'd be easy to possess her right there and then.

You slowly creep up to her and you make your way up the couch. Without any hesitation, you lunge at her, making contact with her body and you feel yourself dissolve into her skin. You hear a small yelp from her, as she tried to react to your sudden moves, but to no avail. Your vision darkens as you take control of her body, and eventually, it returns, along with a number of familiar, but at the same time, foreign sensations. You look down at your body, and after moving some of your brunette hair away, you notice a colorful dress covering your perky boobs.

You did it, you were now in Tina's body!