[He shrugs a little bit. He may be drunk... mostly... but he's not dumb enough to tell his brother exactly what happened in enough detail for his friends to get in trouble.]

I was visiting some friends. They had a drink, so I thought having a drink with people I trust wasn't so bad. And... we didn't realize how much we'd had to drink until we were already done drinking it.

[It's... enough detail. But he's not going to tell Takatora just who it was that he was drinking with....]