I am sure "hate" is wrong. The scene in spoilers you mentioned makes this rather clear. Hate doesn´t fit the label, I personally think Mhy is something like a "hotness", "sexual desire" score. I still try to think up possible German terms for the abreviation here, but currently draw blanks. Words beginning with Ypsilon are megarare in German and normally of foreign origin or names, since in German Y is spelled like a German J if it begins a word.Wondered what Mhy stood for, too. Hate is a possibility, except the finger scene pushes Mhy +2. Would she really hate free morning finger-fucking almost as much as being turned down for sex? (+3) Might need a woman to weigh in on this...
As said, I think that variable is a desire counter.