one who perpetually attracts assholes or, in a more positive light, one who is able to easily get laid.
1. Dude, all your friends are idiots...you're such an ass magnet.
2. Dude, I saw those chicks hitting on you last night...you're such an ass magnet!
Someone perpetually stuck to their boss's ass; toady; brown-noser; syncophant
Dude, John is such an ass magnet. If the boss stopped dead in his tracks, they'd have to pry John's nose out of his ass with a crowbar.