How did "adult" themed shows get on CITV?

Back in the 90s there were some shows on Children’s ITV (CITV) that had some fairly adult themes.

Round the Bend was quite notorious, with many of the jokes doubtless going over the heads of the young viewers. Some were simply references to things they wouldn’t have known, such as the Terry Wogan parody "Wo-gan the Barbarian", and some went as far as sexual innuendo.

I remember another show (but not its name) set in a school where the teacher accidentally played a pornographic VHS tape. A scantily clad man carried a scantily clad woman over to a bed before the stop button was pressed, while the class reacted with glee.

At the time I thought it was all hilarious but looking back I’m kind of amazed how any of this got broadcast in the first place. Did CITV have lax standards and checks on content at that time? Were the producers of the shows deliberately trying to sneak it past them?