Apathy

[Offler]

The card says "at the beginning of upkeep you may discard a card to untap enchanted creature".

Can i repeat this process (by tapping untapped creature to activate ability and then discarding a card)?

[Jaynel]

No. Here's the Oracle text:
"Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
At the beginning of the upkeep of enchanted creature's controller, that player may discard a card at random. If he or she does, untap that creature."

One trigger, one chance to untap.