"Didn't really isn't the same thing as didn't at all," James pointed out. He didn't outright call Sirius a liar, but it was implicit in the Look he gave him. "Look, I know he was a prat who made horrible decisions and did horrible things, but he's your brother, right?"
It was a rhetorical question, but one that required more Firewhiskey. They'd go through the whole bottle before the night was over, but that was okay. "Now, even I'm not optimistic enough to think that he's changed; in fact I'm pretty sure he's the same arrogant snot-rag he was at Hogwarts." He took a sip from his glass. "But he's your arrogant snot-rag, right? I just don't want you to regret not opening any doors that might be unlocked now."
As metaphors went, it wasn't James' best but it got the point across well enough.