You could structure a thoughtform lover, that will avoid all the risks of demons completely, she may take on life of her own over time so be prepared to let her go when you no longer want to have fun with her.
Get to the point where you can see her (in your mind’s eye) and feel she is the same each time, then make a new topic asking how to work more with a thoughtform being.
This is my opinion, not “advice” - it seems to avoid some of the pitfalls you are concerned about, and could be just as useful.