Being the child of deaf parents brings a different set of experiences than that of children of hearing parents. Learning American sign language, for example or taking on adult-like responsibilities gives the offspring of deaf adults a unique view of things compared to growing up in an all-hearing household.
One fairly common experience among the children of deaf adults (CODA) is the early and liberal use of foul language. With parents unable to catch and correct this bad habit, children repeat what they've heard from the older kids at school or the playground and there is almost no barrier to repeated utterances around the house.
In some ways it's like the viruses and bacteria that children constantly bring home from school but in this case, the infection is nearly impossible for the parents to see and do anything about. Fortunately many children are still very indiscreet and eventually another adult (perhaps a neighbor or adult in a shopping center) will overhear and, recognizing that the parents are deaf, intervene with the bad news for the parents: Your son and daughter cuss like sailors.
Of course things are different today with the way foul language is liberally strewn throughout popular media. But back in the day an eight or nine year old cussing out his younger brother at Kmart might attract a lot of unwanted attention. But it doesn't seem to any longer.
Deaf parents can't overhear anything their children do and that puts them at a disadvantage not only because they miss those endearing utterances from toddlers that make us all smile, but also because they aren't aware when their children need to be taught good manners. For example it is common for a very young child--maybe 3-4 years old--to say something like the following in a public place: "Mommy that man standing over there sure is fat!" or "What happened to that lady's face, Mommy?" Most parents quickly put the kibosh on this kind of thing but deaf parents don't necessarily notice it if the banter takes place between two children. Anything like that spoken or relayed from child to parent (I would hope) is extinguished, but when the 4 year old says it to his 6 year old sister, it can be embarrassing.
But without any barrier at home to put the kibosh on childhood cursing, it quickly gets out of hand. And the first that deaf parents learn of this new habit is often from the (hearing) neighbors who might either tell the parents, or tell the children directly to put a sock in it. Sometimes they can't resist foul language themselves when offering this corrective measure.