Not the most adult response, but since when were siblings required to act mature around each other anyway? As far as she was concerned, that wasn't anywhere in the sibling contract, so Ron could just suck it up and deal. He'd probably whinge and complain regardless of what she did.
So yeah. Whatever.
"Going lush solitary is lame and dull." She wrenched the firewhiskey back out of his hand and took another drink. Percy would likely have fainted dead anyway by now, but propriety be damned.