I'm pissed but misunderstood

Today ah, I didn't realise someone actually laughing at me daily when i was presenting. Not only me but others also he laughs at.

I was in mass conversation with some of my classmates during presentation time. Each team's turn to present and in mass chat, my classmates are gossiping about each person when he's presenting. Lol... Everytime like that... Then finally they gossip about me when it is my turn to present -.-

After my team presentation, I went back to seat and scroll up the mass conversation.

"someone laugh at steven presenting"
"everyday he laugh sia"

lol... then I was pissed, quitting conversation.
But this night, i search through the msn history and see carefully as if I may not scroll up further more.

"someone laugh at steven? that is mean!"
"not only him. someone laugh at others too"
"wah. he retard or wad"

lol. I think I misunderstood them as I thought only me he laughs at but actually he's retard lol. At least most of my classmates are supporting, thanks. And I want to slap his kukubird who laughs at me.