Neil Lennon has made it clear it had better be his last - or else his dream career in the Hoops will be much shorter than the striker wants.
The 23-year-old was filmed in a pub before the Edinburgh derby last weekend singing a song about Hearts going bust.
The SFA have cited him for it, and Celtic will defend the player at a hearing later this month.
However, Lennon has made it clear to Griffiths that, while they do not believe he is in breach of any SFA rules, he has acted in a manner which is well below the standard expected by the club.
"Look, we've all been guilty of doing daft things at times," said Lennon. "But that's his one strike. I don't want him doing any more."
Lennon declared when he signed Griffiths in January that he believed he could manage the player, who arrived at Parkhead with significant baggage involving police and the SFA.
Now the manager is determined to hammer home that he is walking a thin line.
Lennon insisted the player has to be smart enough to change his ways, saying: "He has to, otherwise his career at Celtic won't be as long as he maybe wants it to be.
"While he may feel he hasn't done a lot wrong, he understands the reasons why we are disciplining him.
"I know he acts daft, but he's bright enough to understand that. I want him to make the headlines for the right reasons, that is footballing reasons.
"He's made a good start, but I don't want him to get carried away with that."
Lennon is only too aware how much focus there is on Celtic players.
He needs those who join the club to be equally as savvy. This incident is one he categorises as daft rather than serious. "But he's got to stop being daft," was the important caveat.
"There's a code of conduct he has to adhere to now. He did cross the line in that aspect."
Griffiths has been fined, but Lennon revealed: "I haven't hammered him or overemphasised it. You have to give players a bit of space as well.
"He knows he's done wrong. But we've had players here who have done a lot worse.
"We've dealt with it, drawn a line through it, and we will go and support him at the SFA hearing.
"But I'm not going to have these conversations with him time and time again."
While Griffiths pays the price for his misdemeanour, those who verbally abused Lennon and threw objects at him as he watched the Aberdeen v St Johnstone cup semi-final at Tynecastle in February will not be brought to book.
That disappoints the Hoops boss. "I always felt it might be difficult to pinpoint someone throwing the coin," said Lennon.
"I'm annoyed. I don't apportion any blame to the police, but I do feel as if some people have got away with it."
Meanwhile Dundee United manager Jackie McNamara has told his players not to expect an easy time when they face Celtic at Tannadice Park at lunchtime today, despite the Hoops having taken the title with room to spare.
"Celtic will want to win it because they are a group of professionals who always want the best," he said.