How can you Know
I don't think there is any way to KNOW
a player is bluffing a specific hand in
online poker
sometimes you can pattern a player who frequently bluffs,
but it is difficult if they play the same way when they have the nuts
The showing the bluff is just their psych-game -
some players love to needle other players,
hoping to get them to call into their hand
when they are NOT bluffing
Just try to keep your cool
and hold on till YOU have the nuts!
TC