Ok so one day, and by one day I mean bi-weekly, Checkov and Sulu play the ‘how many times this shift vill ze keptin get up to talk to or look at Meester Spock' 

Special points for lingering stares lasting longer than 30 seconds, unnecessary body contact and declarations of undying loyalty. 
(Bonus round- forgetting that the rest of the bridge crew exist in the middle of a crisis). 

At the end of each shift they tally up the scores and hand out the winnings within the betting pool. 
(there may or may not be a separate betting category named 'how long before the just get married’)

Neither Spock or Jim can quite figure out why Checkov and Sulu keep shouting out random numbers mid shift while failing at suppressing grins. Both independently ask Bones but he’s as tightlipped as an Aldebaran Shellmouth about it.