Smell off yer lack boy
Heard in Waterford
Probably the worst insult you can give a yungfella and will almost certainly lead to one getting "their go"... an appropriate response to this expression might be "Yer mudder!"
Smell off yer lack boy, go 'way an' have a wash!
There is a most offensive odour emanating from your person, young man; kindly go and bathe.