It really is no longer than five minutes, but that's enough time that Raiden isn't being over-stimulated and can start to come down from the drunken stupor he'd gotten himself into. There seems to be something more to it, though. You came back. Snake raises an eyebrow. What, did Raiden think he was going to escape out the window of his own apartment and run off somewhere to avoid dealing with him?

Not that Snake can expect drunk logic to make sense.

"Yeah, I did," he says quietly as nods to the glass of water. "Drink that. All of it, if you can. And change into those clothes. I'll wash the ones you're wearing in the morning."

Did he just imply that Solid Snake, legendary soldier and spy, does his own laundry? Possibly so.