Just saw a guy masturbating on a bus, how do I tell his girlfriend?

So I'm gonna throw names in so it's more interesting because this happened to me in real life. <br><br>It was a long time ago when I was probably 14. I lived in a fairly safe area, everyone was well off, and we all kept our houses immaculately clean. <br><br>I missed the bus to school and so I had to take the next bus. There was a guy going the same way as me, let's call him Andy, sat on the first seat on the right. <br><br>The bus stopped at the next bus stop presumably and let someone on. It didn't move after that. I looked back to see if there was going to be a problem with the bus but there wasn't. <br><br>The driver walked back to the guy who got on at the last stop and then the bus left. I assumed he had hitched a ride and the driver gave him a ticket.<br><br>When we got to the bus station, we had a choice of either going one way or the other. Two buses pulled up, one drove to the left and the other to the right. A girl, let's call her Claire, got on the bus to the right. Andy didn't know her but apparently he did know her from the school he goes to presumably. <br><br>He told me he had to get off at the next bus stop whenever it came, which he did. I saw him get out which I felt a bit bad about, but I didn't tell him to stay on. <br><br>The bus eventually stopped at the next bus stop and let someone off. I noticed that the guy who had hitched a ride earlier was still on the bus but he was standing up. He was probably going to the next bus stop and before that stop came, he was going to get off at the bus station. <br><br>When we arrived at the bus station, he didn't get off. In fact, he did something else. He started fucking the girl, as he had pulled off her underwear because he was apparently fucking her from behind. I could see this from my seat because I was on the left and they were on the right but to the left of the right side so they knew I could see them. <br><br>The driver came down with some metal bar and said he was going to call the police. I listened to the entire conversation going on in the rearview mirror because I couldn't hear it properly. He started fucking her on the bus, I could presumably hear them, and the driver came down and started presumably talking to them. <br><br>He came up with the metal bar and hence the fact he said he was going to call the police. The driver kept going and I listened to the conversation. They had been fucking since they got on the bus and literally sat down on the right side and started fucking. <br><br>Apparently what happened was when the driver came down, they told him that they weren't fucking and he believed them. I didn't believe it because they were clearly fucking but I didn't want to be the one to say anything. <br><br>The driver told them to behave and he didn't tell them to get off. The driver drove down the street and eventually Claire and the guy presumably got off at their bus stop. <br><br>The driver didn't get off at the next stop as he said he was going to and the girl didn't tell her boyfriend. <br><br>I listened to the conversation between Andy and the girl. He asked her what she was doing on the bus and she told him she missed her bus and was going to spend the day at the beach. She didn't tell him that she fucked a random guy on the bus. <br><br>A few months later, I saw her boyfriend which I felt bad about. What was I supposed to tell him? Apparently the driver noticed me watching her from my seat and the driver presumably saw that I was listening to the conversation. <br><br>He told me to pretend I didn't see anything and I listened. What else am I supposed to say? I told someone about it but they didn't believe me so I just stopped talking about it. <br><br>I feel bad about it because I saw it and I don't know what I'm supposed to say to her boyfriend.