This is a recent behaviour trait. I think she has Lewy Body Dementia as sometimes she is really with it and other times behaves as though she's severely mentally handicapped. I never know if she's acting or if her problems are real. We think she's dying and the very next day sits up and does her make up and wants to get dressed (she does forget that she's bedridden).....Now this awful sexual behaviour.....I'm at my wits end !!
Maybe she has a UTI?
With this being a new behavior maybe take her to the doc for some blood work and a checkup?
I'm not sure it will be a consoling thought, but at least this behaviour can't do her any harm, or do anyone else any harm beyond embarrassment.
I looked at your profile but can't see any information about your aunt's health. Are there any formal diagnoses to go on? When did she become bedridden, and why?