Saying things under their breath

Lately,mostly on childrens show's my sister is watching. I have heard people in cartoons etc say things under their breath,these things usualy sound like they are saying something else in context to what's happening but if you listen good enough you can hear them swearing and everything else. does anyone notice this?

My daughter and her friend started calling each other "holes"

Then I watched the episode on the Regular Show where they say "pissed"

They are only 11 yrs. old and I am sure they have heard much worse language, but not at home.
Therefore, the Regular Show is off limits in my home simply because I don't know what they will say next.

I just wish Cartoon Network would give parents a little warning that these shows may be a little edgy.
They put them on at a time when they know even the youngest are watching cartoons. That is my only problem with it.

How the H do we deal with this S?
Monitor what our kids are watching. Closely.