I think it could work realistically if you treat it more like fuck buddies and she's a sub.
Like a set day in the week, or when you or she's in the mood. You come over, or she does. And she's yours for that time for whatever you want. (Some rules ofc)
Also this is from a cucks view from a relationship
But I'm sure there are some single subs who wants this full time.
And if you watch Po*Rn every white female wants this!
(jk)