Ned Poins, informal intelligencer to his sometime-boyfriend Henry V, knows more than most. He also knows a thing or two about tennis balls.
The prince must put away childish things. Ned knows he's one of them.
"I suppose it's safe to assume you aren't here to ransom me."
Poins kills a man; the rest doesn't matter, and the prince must carry on.
Too late for Christmas, too early for the new year. (Or, Hal makes himself inconvenient in as many ways as possible.)
Well, it's not quite a hairshirt.