Professor's weird behavior I have just started a thesis-based masters degree.  

My supervisor has asked me to help with another student's project. So I am working with another student of my supervisor. We work together and send him a report weekly. We send reports on time.

One time our report had a mistake, the professor got mad at me (at that time I sent the report to him). He told me unpleasant things and I got really disappointed at that moment and it happened two times. It was weird because firstly he was very good with me and this behaviour was very unlikely. Secondly, he was not mad at my colleague (another student) we were working together.

Both of us wrote and sent that report and both of us made that mistake. Why he was not mad at him? did he tell any bad thing about me to the supervisor?
What should I tell to my professor? I feel very bad. He made me feel that I am useless.

I heard that my colleague has a bad reputation of gossiping about others to the supervisor.

I should add that my colleague, thinks that he is the boss in the lab and he sometimes bullies me and tries to correct me in everything even when we are filling a form which is not related to the project.

How can I handle this situation?
It sounds like an unpleasant environment to me. But still, this is one incident, right? So it might make sense to wait a little longer and see if this was a one-off or fits into a pattern.

If this turns out to be a pattern, you shouldn't stay in this lab beyond your Masters degree. If you really need a publication from your Masters degree (something that's not at all required in my field, for example), you should actually consider going to a different lab. If you feel like your supervisors anger, or your colleague's backstabbing, is too much, go to another lab as well.

While you are in this lab, there is surprisingly little to 'handle' about the situation. Just do your work, as separate from your colleague as possible, ignore your supervisor's anger but do try to get as specific feedback from them as possible, finish your Masters on time, get your recommendation letter and leave.

This answer sounds incredibly jaded and that's because it is quite self-centered: this is just a way for you to get through your Masters as painless as possible.