#20 – Don’t come over holier than thou, like ‘you’ve lived in sin for so long that we thought you were married already’. No, you knew they weren’t and you aren’t funny.
#19 – Never get the names of the couple wrong. You may not remember one of the names if you don’t know that person well or if they have a hard to pronounce name. If you’re not 100% sure, just don’t call them by any name. ‘The happy couple’ or ‘the bride and groom’ will do if talking about them.