Do you think I should go to the Party?

Today, I was invited to a party at school. We have some Korean Exchange Students, and they are having a big good-bye party at their house. I got an invitation from Lyle; he was not a Korean. I thought it was a fake because it was hand drawn. I asked my other friend Tyler if this was a fake. His, along with everybody else's invitations, was the same. Same time, same address, and same design. I asked him why I was the only grade 5 invited. Matthew (korean), was a grade 6 (5/6 split cl), I asked why I was invited. We are friends, but I was a little suspicious. He said " I invited you because you are cool, and so I wouldn't have to invite Siobhann (Pronounced Shov-on)." That's the statement that makes me wonder. "And so I wouldn't have to invite Siobhann". He also said I am cool, but should I go? I got a real invitation, but does he really want me there? I really want to go, but I won't go if they don't actually want me there. Should I go, and can you kinda explain the situation, it's a little confusing? Help! It's eating at my brain! SHOULD I GO !?!?!?!?!?!?