Why won't this dog like me?

My boyfriend's dog HATES me! Literally. He has bitten me before, and when I first met him he growled, lunged at me and was snapping his teeth at me. He refuses to sniff my hand, take bribes (treats) and even makes eye contact with me (a sign of dominance, I assume). He is an abused rescue, but he warmed up to everyone else and it's been 5 months and no improvement. The "poor" thing either is in a cage or has a muzzle on around me. He barks, growls, and has bitten some other people, but I'm the only person he hates. Everyone who lives in the house he loves (even though I practically live there too). What should I do?