Rugger bugger
A loud, posh rugby fan, usually in a pink shirt and a gilet, usually roaring.
De pub was full of rugger buggers in pink shirts roarin' about de lineout.

Shall I translate it into posh English for you, sham?
Oh, how lovely to see you. Here it is in posh English.
The public house was overrun with boisterous rugby enthusiasts in rose coloured shirts, declaiming upon the lineout.
Questions
What does rugger bugger mean in Ireland?
A loud, posh rugby fan, usually in a pink shirt and a gilet, usually roaring.
How do you use rugger bugger in a sentence?
“De pub was full of rugger buggers in pink shirts roarin' about de lineout.”
Updated
On the list: Irish slang words · Irish slang for man