hellooo, this is such an interesting ask and i'd love to talk about it! because yes. i have thoughts. first i obviously need to say that 1) i'm not a classicist, 2) most of what i'm about to tell you is from my own research and i won't have a full vantage of this time period that a historian would. i highly recommend reading this article on curio's father, and these articles on curio in general. cicero writes about curio posthumously in the brutus. the 3 letters he wrote to curio are certainly very friendly, and caelius's letters to cicero also frequently mention curio in fond terms ("our curio" and such), as late as 50. also, i'm about to get really really long-winded, so bear with me. i like curio a normal amount.
it's tricky to date the entire timeline of curio's early relationships with antony versus cicero, but he could've been associated with antony well before he and cicero became friendly. during the late 60s curio entered the political scene as very pro-clodius, and cicero clearly didn't like that; we get the hostile "filiola curionis" letter in 61, which is a Very Interesting thing to say about curio, especially in a letter not intended to be published. but in 59, curio filius is studying under cicero, now in a positive mentorship relationship, and probably much closer to cicero than he was with his father. 59 is also when some scholars date the debt scandal, so to cicero, antony was probably yet another of (multiple, considering clodius) "bad influences" keeping curio from proper roman behavior. but cicero was still willing to step between curio and curio's father to resolve the debt conflict (if we are even to believe cicero—but something probably happened at that time that established a debt of personal obligation between curio and cicero later on. so we'll just run with it). one of the conditions cicero (claimed to have) laid down in the entire debt scandal, whether true or not, was that curio would stop associating w antony afterwards. obviously that didn't happen, but the next year in 58, antony left for greece. so take that as it is.
it's definitely not so surprising that curio and cicero were close at the time, and that this continued after curio's father died, especially because there's good reason to believe neither curio nor cicero liked curio pater very much.
cicero was formally friends with both father and son, but he probably considered curio's father to be a bad influence on him for not putting any great interest in educating his son, which is all tied into the opinions he writes in the brutus when both curio pater and curio filius were dead.
after curio's tirocinium fori with cicero, the positive relationship continues throughout the 50s as curio's politics... evolve. in this period of time he probably took a leaf from his father or cicero's book and grew more moderate, but he was still friends with cicero, antony, and clodius. and could've been in the field to support milo. which says a lot about him. (cic. fam. 2.6 iirc.) and he was still friendly with cicero after he married fulvia, getting into the 52-50 period. curio seemed to have a mostly-strong handle at keeping strong friendships despite his political differences.
we also know thanks to caelius that curio was beefing with the antonii in the year 51 over curio running for the tribunate on anti-caesarian policies! this was probably lucius and/or gaius but they would've been representing the interests of the entire trio. it's also likely that even while curio was adopting more caesarian (or at least anti-pompeian) politics he did not fw caesar himself.
curio and cicero's relationship seems to get more complicated by mid-49 in the civil war, months before curio died—and a lot of things obviously played into this, but curio's relationship with antony could've factored into one of the many reasons he went over to caesar. cicero was not a fan of that. (there's a really intriguing letter from April 49 where cicero describes curio's mid-civil war sleepover at his house, and there are lots of complicated feelings on all sides. curio also wants pompey dead, again.)
but after curio's death, cicero represents curio positively in writings like his brutus—where he praises curio's talents but critiques his failure to emulate his father and, in short, live up to his potential. he throws around some words with a bit of gendered undertones (virtus etc) in that section, which i find interestingg if you compare it to the other gendered language he uses curio in the late 60s. also (i might be getting off-topic, but once antony's involved, i think it's a little relevant) when cicero does give these opinions, the way he genders curio, so to speak, seems to be conditional on curio's political activity and cicero's judgements on his morality in accordance to it. he went from filiola curionis to curio filius a while ago, but cicero still holds reservations. you see a bit of this when he starts discussing curio as an orator in the brutus, which is much more positive towards him than cicero's opinions on curio's father, but not without critiques on the kind of political career curio pursued. and that's layered with words like virtus, in which he pursues fame/grandeur/attention instead of the former. again, to me. interesting.
in general, curio was constantly straddling two different polarities at once in both his personal and political associations. there's a constant theme in most of cicero's writings about curio where he considers him a talented young man, definitely worth emotional investment, but open to misguidance, political corruption, other sorts of fooling around. it's no surprise that people constantly compare curio and caelius. and when it comes to how antony influenced cicero's opinions, you can imagine who cicero also thought was another bad influence on curio.
this is uhm. SO much longer than it probably should've been but there's a LOT to talk about. thanks for asking, and i hope this helps in some way!!! <3
