I also learned alot about Umeda muse last night when he was sort of out with Akiha. I learned he likes tying up Akiha (*coughs*), I learned that he is all over Akiha when Akiha is evil to models and can't keep his hands off of him.. and if he inadvertantly bites Akiha enough to draw blood, or Akiha bites his lip enough to draw blood, Umeda will gladly lick it off. Oiya, the kink. (Though as Mish pointed out, Scorpio/Saggitarius matches seem to be very much like that.. since Scorpios are kinky and Saggitarius' are very eager to go along with it.)
My Umeda muse loves his Akiha muse.. he just has funny ways of showing it (like kicks and verbal abuse...). It's a good thing that they are so in love with each other and Akiha knows that when Umeda is being mean, it really = love.