ha! i actually have some stuff planned re: calpurnia's betrothals. pretty much every suitor that's turned up she's swotted in, taken one look at, gone UGH NO, and twirled back out like a bitchy skirt tornado. part of that is she's a picky brat. the other is that she's secretly a power player in the kingdom and nobody wants her to end up in the wrong hands.
however, if you'd like him to be someone she was promised to at one point or is being propositioned for the job, there have been a lot of those, especially since her older brother and mother have no idea of her real value/maneuverings. as for the bickering and sex: the bickering, absolutely. the sex i'd have to see how they play off each other before deciding.