Here is all the information you need. From the time kids are potty trained they know urine goes in the toilet and gets flushed away. 17-18 year old young men, not kids, know this and know better than to spray, poor, or whatever happened, urine on another person. It doesn't matter if they have a history of bullying/harassment or not, the fact is they knew better. Once you break the situation down, its pretty simple.