Astral sex is real. You do not have to be in the astral too.
There are polygamous and monogamous succubuses. Like a relationship with a demon that is intrinsicly about sex. Having other "things" isn't advised, as a demons sexual appropriate is more than enough.
They will also care for you if you have a good enough relationship. Or you can ask Satan for one who's already willing to care in some aspects.
Oh. And if you pick monogamous it better be fuckin monogamous you don't want the partner you had (cheated) sex with to die.
Or more creative things