Just mark your work as mature content and you're good. It's in the name DeviantArt, "Deviant," by definition adj.— "departing from usual or accepted standards, especially in social or sexual behavior."
I've seen way worse on here than nipple. I seriously have 57 tags muted and counting, some profiles blocked due to absurd and disgusting content, but to each their own I guess.
male nip is ok, you can have 2 or more male nips in your picture withotu it considered nudity
female nip : be cautious, on all major platforms, there can be only one nip, and that is under certain condition. 2 nips or more will get the nipple bots will detect you, and flag you as NSFW just like in minority report yes, one nipple is a warning, 3 warning is a red ball, red ball means you go to prison
and beware of the anti-nip militias who will flag your picture, the automated niplle prevention system will then auto flag you as NSFW
depends on cultures, I would say the nipple though will make the difference between nude / not nude
all major platforms like facebook & instagram have nipple detector systems, nipple detection bot programs who crawl the www searching for nipple
if you can pass the facebook nipple detector, you're good
if not, you're running into problems, except if you flag as mature / nsfw, especially if the nipple detection systems can count 2 nipples then you're in for some serious problems you will get less audience tho and different also, because the crowd who doesn't mind a nipple is fdifferent from the anti-nipple people
I think if it's a context of gesture drawing or artistic nudity you're usually ok but when it's a sexualized context you usually want to put a mature filter on it. Some people will sometimes flag artistic nudes as mature too tho so safest bet is to put the filter regardless.