Keep it clean. Don't mention the ex. Compliment the bride and bridesmaids.
Importantly, nowhere is it written that the best man shouldn't rap his way through his speech.
Which is just as well because we would have hated for Adam Jack, best man at his brother Sam's big day in Ayreshire, Scotland, to be discouraged from delivering his unique ode to the happy couple.
Beginning by asking the DJ (or possibly wedding co-ordinator) to 'drop that beat', the kilt-clad best man launches into a funny and touching rap that not only manages to welcome everyone, introduce him as best man and compliment the bride, bridesmaids and maid of honour, but also encapsulates the couple's love story from when they met and beyond.
"Chatting up the girls was a mystery,
Sam picked out Leo and the rest was history,
'Cross the US the pair have travelled the world,
And maybe soon we'll see a baby boy or girl,
Cause I want to be the fun uncle 'Ad'
Helping you guys out in the good and the bad."
The video, by MacDonald Studio Wedding Films, was shared by groom Sam and has since had nearly 10K views.