He counts the drops to see how many drops will fall after Sungho comes back. He said "11 times"
Because that's how many drops fell after he came back, not how many times he raped him.
Since he doesn't have a clock or anything, that's what the bottle is there for
No, the water reaches 2 cubes of the water bottle. That's how he counts the time. The 11 is the number of time that scarred faced wrote only the dates and no events in his diary. And scarred faced also marked it on the calendar. You can see some of the dates on the calendar has been written over with another number in red ink. I think it's the time that scarred faced had raped Dohyun in counting since he kidnapped him. So there are 11 times more until...something else will happen I guess?
That something else is a scary thought. XD
What happens after 11 times is the real question. I don't really think he will stop this after 11 times tho. I mean no psychopath does ever. (￣∇￣")