1. You really disappointed me, you actually cheated me behind my back!
2. It's disgusting that you're doing this, and our friendship is no longer pure.
3. You really disappointed me, I never thought you would treat me like this.
4. I was really deceived by your hypocrisy, I didn't expect you to cheat me behind my back.
5. It's really chilling for you to do this, I didn't expect you to cheat me behind my back.
6, I was really blind, I didn't expect you to be such a person, and you actually cheated me behind your back!
7. It really hurts my heart that you are doing this, and the friendship between us is no longer pure.
8. It's really infuriating that you do this, you are not qualified to be my friend!
9. It was an eye-opener for me that you did this, I never thought you would do it.
10. It's really infuriating that you do this, I didn't expect you to cheat me behind my back!
11. I was really shocked by your behavior, I didn't expect you to trap me behind my back.
12. It's heart-wrenching that you're doing this, and the friendship between us no longer exists.
13. You really disappointed me, I never thought you would do this.
14. You're so irresponsible, I didn't expect you to do this.
15. You are so irresponsible, I didn't expect you to treat me like this.
16. You really disappointed me, I didn't expect you to do this.
17. I really saw the wrong person, I didn't expect you to treat me like this, it's so sad.
18. You are so irresponsible, you would treat me like this.
19. I am really blind to believe that you are my friend.
20. I was really deceived by your hypocritical behavior, you actually cheated me behind my back!
21. I'm really shocked by your behavior, you actually cheated me behind your back!
22. It's disgusting that you're doing this, I didn't expect you to trick me behind my back!
23, you are so irresponsible, you will actually cheat me behind your back!
24. It's really infuriating that you're doing this, and the friendship between us no longer exists.
25. I didn't expect my best friend to treat me like this, it was so disappointing.
26. It's really chilling that you do this, and the friendship between us is no longer pure.