Linfield manager David Jeffrey was in apologetic mood at the weekend and no wonder.
You expect the unexpected in Irish League football but that amazing YouTube video took us all by surprise.
It was certainly one of the most entertaining weeks the domestic game has given us in recent memory.
Jeffrey said sorry after the video of him singing a song about Glentoran player Jimmy Callacher went viral.
The Linfield boss is heard singing "thank you very much for Jimmy Callacher" and "thank you Glentoran".
Callacher had already ruffled Glentoran's feathers by indicating that he wanted to leave the club and join the Blues. The Glens responded with a strongly worded statement on their website outlining their anger with the player.
Jeffrey will now think twice before bursting into song when he's offered a microphone again.
There's no doubt it's an embarrassing episode for the Blues boss and he was left with no option but to sincerely apologise.
The Boxing Day battle at the Oval featuring the Blues and Glens has been given a hot and spicy kick by 'Callacher-gate' but there has always been intense rivalry between the two biggest clubs in local football.
Of more concern to Jeffrey will be how his behaviour is judged in the Linfield boardroom for that's where he needs friends, not foes.