The act of 'killing it' would be performed after a joke is being told when everyone has just
laughing and 'the killertries
to be funny and adds on to the joke in attempts of making it funnier. This of course
is not funny, and in turn, 'the killer' was just
a big buzzkill
, otherwise known
as 'killing it'
Person 1: Dude, Blake
thinks he's so funny
but no one ever laughs at him...
Person 2: Seriously, he tries to make everyone laugh, but all he's doing
is killing it.