원문 - 영어 - The answer is that you don't know the truth. But...

You ask for the answer. You already know the friends around you act strange. These persons are lying to you. Just call Yusuf's roommate or his girlfriend and ask them what they are hiding. They know the truth. But they are scared to tell you. Try it. I only want to help you because i feel so sorry for you that you were so blind you didn't see it.