Are you one of these drunken people?

..
Running a train is just taking turns on a ..usually it doesn't take place with only 2 guys though, but I guess everybody does it in a different way..the least I've ever seen is 3 guys, and the most I've ever seen is 9 IIRC..it was quite disgusting..
Let's say that we believe him and that he was having consensual sex with her before she was vomiting, continuing the act while the girl is vomiting is disgusting either way..it's not as bad as rape, but come on, she's throwing up..
The fact that he got kicked out of school is relevant IMO..there was definitely something serious going on for him to get kicked out of school, so I tend to believe that he ran a train and the passenger got train sick..
Worst case: They raped this girl..
Best case: They ran a train on her while she was vomiting..
Both cases are disgusting, even if one isn't as bad as the other..