why you should watch what you say in front of mini people....i mean children

My younger sister will be turning 48 next week and is already a grandmother.
Her only child had his first baby a few years ago.
She left Singapore years ago to go learn hairdressing in London and she never came back...  She met Pete the Greek Cypriot and settled in London.

grandson:                    YiaYia  YiaYia  (thats granny in Greek)
Sis:                             Yes Dorian
Dorian the grandson:   Booya motherfucker!!
Sis (trying really hard not to laugh) :  Right!

Pete the Greek Cypriot grew up in London and loves his football (soccer to all the philistines) and Pete tends to get rather excited when watching football especially when his team is playing, and by excited one can safely presume profanities will be uttered ....often.
After the Booya Motherfucker episode little Dorian was told that some words were not nice words to say.

Pete the Greek Cypriot while watching football uttered the word Fuck several times.
Little Dorian got up and sat on his Pappu's (grandfather in Greek) lap, took Pete the Greek Cypriots face in his little hands and said solemnly
"No say Fuck Pappu, No say Fuck"

Awwwww