In one episode about plants a girl asks bill to pollinate her.

There is one instance where in one episode an interviewed kid says," unprotected sex" when talking about diseases.

none

I'm a few episodes Bill is clumsy and he falls down a flight of stairs it doesn't happen often though

Did you know that in the rivers and streams episode Bill says "that's a lot of dam power" while talking about how much power dams make? This is because the way he says it sounds explicit and sounds like he's saying it as a lot of damn power.

However, at least one "sucks" and one instance of a character's swears being bleeped.