Sorry that you're having to deal with that. It's why I never really had the guts to get tattooed below what I could cover with short sleeves. I'd say that if you have been fine up to now though, that they'd need something stronger than that to can you, and if you're in there kicking ass and taking names, you should be fine, but I think that looking for something else is a safe bet and if they confront you and you're straightforward (like if they say they're gonna can you for them) I'd just say, look, cut me some slack and let me find something else and I won't make a stink and we can have a nice day. Be sure to tell them that you hope their firings go really well.