I think some psychiatrists say it is, and some say its a load of bull (in reference to the sexomnia thing)
anyway this isnt that, because he acknowledges he is fully concious and that he 'cant control himself/ stop thinking about sex.
That isnt normal though. It really really isnt, to be so completely obsessed about sex, to the point that you supposedly cant control yourself at all.
It would make him extremely dangerous to be around, because there are lots of sexually attractive women out there in the world, its impossible to not encounter people who would attract you, and if he says that when he gets turned on he cant control that feeling, he cant stop that train once it starts running - well where would that leave him??
So no. I dont really believe that. What I believe is that he has a really warped sexual compulsion and you are his outlet for it. He feels that this is your role. that this is just a little blip in the road until its full sexual access all the time.
And I agree that he is working at home because he is keeping an eye on you. He knows something is up/ something is changed.