How to *politely* tell this guy he's not my friend and to quit tryin to hook me up with fat nasty chicks?

So this guy at my job, he thinks I'm just his best freakin buddy. He even wanted me to be the best man at his wedding and be his kid's godfather if he ever has one. He's, quite frankly, an annoying, hypocritical, immature sack of excrement. He married this fat chick after knowing her for a whopping MONTH, and he's just such a clueless idiot. As we've already established, he's into fatties and one day after I have been avoiding this dude for like months, he comes out of the blue and is like "Hey I got you a date to the Christmas party". I thought he was joking, but sure enough he brings his fat-*** wife and her fat, nasty-*** cousin from freakin south central, block-rollin cholo land or whatever and expects me to be into it. It was awkward as s**t and I tried in my own way to be subtle and be like "Yo, I thought you were kidding, this is completely uncalled for". So then later after this weird encounter, a few days later he's like "Why haven't you called her yet?" And I'm like "Man I'm not gonna make this girl think I like her when I don't"

So, what I need advice with now, is how do I make it clear to this guy that 1) I DO NOT like the same kind of "plus size" girls as him, 2) I DO NOT need nor want his help with ANYthing in life whatsoever, and 3) I am NOT his best buddy like he thinks I am?