Luther- he likes to keeps things sweet and calls you sweetheart or sweetie. When you're in a teasing mood, you'll call him monkey boy, but most of the time you call him Luth or handsome.
Diego: when he's being cheeky he'll call you hot stuff or sexy, but most of the time he calls you vida or amor. You like to call him guapo or knife boy.
Allison: sometimes you like to tease her by calling her rumor but more than likely you'll call her beautiful or cutie. Allison loves to call you her starlight (get it, cause she's a movie star?).
Klaus: Klaus will call you "the only drug he needs" or his happiness. You'll call him your favorite junkie or ghost boy.
Five: because five likes to bring up that he's smarter than everyone a lot, you like to call him smarty pants. More often than not he'll call you gorgeous because it makes you blush like crazy.
Ben: before he died Ben would call you sweet pea and you called him love bug. After he died he still called you sweet pea but he'd also call you his reason to live and you still call him love bug.
Vanya: you'd call her shy babe and she'd call you her musical sweetheart.