You're an awful man
Affectionate rebuke for a fella who has done something grand and slightly out of order, like buying the pint you said you would not have.
"You're an awful man" (said when you've turned down a pint but he buys you one anyway)

Shall I translate it into posh English for you, horse?
Hello, hello! Mind the rug. Here it is in posh English.
You are a thoroughly incorrigible fellow (said when one has declined a pint and received one nonetheless).
Questions
What does you're an awful man mean in Ireland?
Affectionate rebuke for a fella who has done something grand and slightly out of order, like buying the pint you said you would not have.
How do you use you're an awful man in a sentence?
“"You're an awful man" (said when you've turned down a pint but he buys you one anyway)”
Updated
On the list: Irish slang phrases