Yeah, your parents are setting you up for this.

You could try talking to your parents and asking for bunk beds like the other poster said, but unless you explain the attraction they might just say no.

If your parents are reasonable people I bet it can be fixed by telling them “ever since I hit puberty sharing a room with sister has gotten harder, and i really can’t share a bed with her anymore, i cant control parts of my body and it’s super embarrassing and weird.”

Not fun, but that should do it.