Hello Monstrocide. My name is Josh, and i've been summoning a succubus spirit for awhile now, almost 4 months. I won't go into detail, but they can bring some seriously amazing sexual pleasure, just make sure you don't mess up the summoning process.
Also, it's not that simple, just randomly inviting one into your life could be bad, you have to be specific for what you want to summon. Google the man Erik Vonroth and sign up for his lesson on summoning them.
Message me if you would like, I have some pointers!