Two
Spock and Nyota were huddled together behind a bush, communicating silently as they decided their next move in the tactical exercise. Neither had been given time to change from their sleepwear when the maneuvers got under way; utility belts with equipment they would need were tossed to them right before they were transported into the game. Nyota was trying not to be distracted by Spock's long sleeved black shirt that clung beautifully to his chest - must have been meditating, she mused - however, he seemed to be paying no attention at all to her lack of actual clothing; she wore only a t-shirt and panties.
Hearing a branch snap on their left, Nyota drew closer to Spock to ensure they weren't detected, too focused on the training exercise to notice that her bottom was now firmly pressed against her partner's side.
The officers decided that separating at this point was their best option and agreed on a rendezvous point. Hearing rapidly approaching footfalls, they implemented their plan; Spock would dart away first, then Nyota, a few beats later, in the opposite direction. But Nyota had unknowingly snagged her underpants on the equipment on Spock's belt, and she froze as he sprang into action, unwittingly taking her panties with him. She turned, throwing her hands over her embarrassingly exposed backside and watching in horror as Spock streaked into the darkness, her panties waving behind him like a white silk flag of surrender.
Spock failed to understand how he was so easily spotted by the Captain, who tackled him to the ground, howling with laughter.