The description of the burning disarm spell says:
This spell causes a metal object to instantly become red hot. A creature holding the item may attempt a Reflex save to drop it and take no damage (even if it is not their turn), otherwise the hot metal deals 1d4 points of fire damage per caster level (maximum 5d4).
Is the Reflex save automatic, or can the target decide to hold on to the red-hot weapon?
The word may there seems to imply that the target has a choice, but it's a bit ambiguous.
Best Answer
The creature that's holding the object that's the target of the spell burning disarm does have a choice
The creature holding the object affected by the spell burning disarm can either...
...or...
Although it seems strange to succeed on a saving throw to drop the targeted object, doing so when the object's affected by the spell burning disarm spares the creature holding the object damage from the spell. Usually, avoiding damage is a good thing; in this case, however, being disarmed may be worse, so the spell allows the victim a choice, albeit a sort of Hobson's choice.
Neither failing the saving throw nor choosing not to make a saving throw prevents the creature from dropping the object normally on the creature's turn. (Bear in mind, though, that the duration of burning disarm is instantaneous, so there's no reason to drop the object subsequently unless fearing further burning disarm spells.)