Graceful Combatant

You can use even heavy blades with speed and precision.

Prerequisites: BCB +1, Dexterity 13

Benefit:  Choose the longsword or the quarterstaff; the chosen weapon becomes a finesse weapon for you (though you can't finesse a longsword in one hand).

You can use your longsword or quarterstaff with the riposte feat (if you have it), even though you wield it in two hands.