Do you mean like "crap" (yeah Perrie says that word a lot lol)? I don't think it's really that bad a word though
I've never heard them properly swear (like the F word or the C word, personally I don't count "sh*t" as swearing as it's quite mainstream now lol) apart from maybe Jesy once or twice. LA and Jesy look like the type of girls who would get some dirty words out of their months when they get feisty lol. As for Jade, the worst I've heard from her is probably "what the hell" I don't think she even says "crap" does she?
Jesy has blurted the F bomb a few times, but it just makes her more human. I dunno, I think people have this fantasy about Jade and Perrie being little untouchable princesses but I think they are much much feistier, they just havent shown it in public yet.