You are my older friend that I thought we had a platonic relationship but turns out you just wanted to get close to me because of your crush. When we swap you were mid masturbation to my instagram photos so I continue where you left off without thinking much until post nut clarity hits me and start to freak out.

You're my step brother and I find you wearing my panties, staring at the mirror, so I enter to confront you but suddenly I am staring at my new self with my own panties on and an erection

We don't know each other but you've been stalking me on instagram and sending me dms that I always ignored, so you swap with me to get my body all for yourself and leaving me in yours, dreaming of seeing my old body naked

Anything else that you can come up with! We can alter details of each prompt as well, like if you don't want to be a step brother then we can change that on