It’s honestly disgusting, something similar happened to me on a trip to an amusement park 3 years ago, when we were coming back to hight school, it was like 9pm and we were just having fun on the bus singing and dancing, until suddenly I felt like someone grabbed my ass on 2 different occasions, but the a place was so narrow and dark that I couldn't see who it was, I felt very uncomfortable the rest of the way, when I told my friends, they told me that they would have felt successful because in that area of the bus only the girls were celebrating. I get along much better with girls than with boys so that's why I preferred to stay with them, but I didn't think that would happen (I’m gay btw)