Anger- Anger cancelled???

Okay so any of you remember that episode from FRIENDS where Phoebe takes up some lessons and asks Rachel whether she will like to accompany her, she does and goes late without doing homework and asks Phoebe's help on gist of the book. Ironically tutor picks up Rachel to answer the question, she gets all the accolades from tutor. Phoebe is next to answer same question and she feels lose of words feeling Rachel stole her answer ? Remember???

Okay so I went through a similar kind of incidence followed by a similar kind of feelings yesterday.

As you might know that I am trying to learn a little bit of Dutch and taking lessons for that ( Ok if you didn't know, now you know). We were given some homework from the class and fellow-next-to-me didn't finish it till last moment. So then he asks me to help him in completing it and I happily do. But then it seems its taking too much time and it's about the time of class to start...

Fellow-next-to-me : ok let me copy down from your sheets
Me : but that way you won’t be able to learn yourself
Fellow-next-to-me : for this time only, from next time I will complete it on time
Me : ohhh ok (hadn’t any options as he had already took my sheets and started copying)

So he copies it down. The class starts soon ... Tutors asks us whether we have completed the homework, all says YES, and Tutor starts all the questioning on homework, which this fellow-next-to-me replies proudly.

Now comes the end part, which is to write some sentences about you... sorry not about you but about what is "not" you or "not" about you.... yeah practising negative replies.
This guy's turn is before me and he just reads out all the sentences copied from me!! ( can you imagine??? he actually copied all those sentences also same to same from my sheet .... imagine my face in red here ) and suddenly now I am left with lose of words on my turn as what I had written he already spoke everything !!! Grrrrrrr
I feel so angry... but but but I cannot be, right? I am in the class after all.

Now the next class exercise starts, and same fellow-next-to-me is my partner in that. As now I am angry I keep the mum and don't talk much. He asks me to show him questions (exercise was to form questions in Dutch reading a given paragraph and ask them to your partner) Again I help him as he asks me but reluctantly due to my anger and only with first part. Now I think he was bored or too much in over-confidence so tells me in a light mood.... ohh ok, it's alright you create and ask the questions in exercise and I will reply.... I say alright and we stop discussing.

Now comes our turn ... funny enough we get second part of paragraph and not the first part which we had discussed. As he suggested me I start with questions.... first question...ok easy enough... second question created from a part of a sentence and he doesn't understand it, third question created from other half part of the sentence and booooom he didn't understand that either (I feel like laughing aloud and saying dude you get back what you do to someone, now you see what it feels like???) ... and then it happens..... A stare..... ( nooooop I know I had felt like but hadn’t laughed aloud, It was all just happening in my mind, feeling and wanting to... all that you know) yeah so he actually gives me a stare and now HE IS angry on me that why didn't I show / help him !!

Ohhh boy, It's me who is angry on you, You can't be angry on me !!! right??? .... THIS IS NOT FAIR!! Not at all fair !!

Can anyone tell me in any chance, does it work in a way that anger - anger ... means two angers cancelled??? Huh?

..