Matt Lavigne, brother to singer Avril Lavigne, says in his unauthorized biography that Avril Lavigne is a transvestite. Matt Lavigne claims that their dad did not want another boy and that their mother dressed the boy as a girl and gave him female hormones. Their mother claims she created the “skater look” for Avril because the baggy pants would hide the fact she is a he. By the time their dad found out, Avril was already rich and famous.
You're exploiting an entire group's gender identity (transexual) for the purpose of insulting someone. It's like how using the word "retard" to insult someone's intelligence is offensive to people with intellectual disabilities like downs syndrome.
Before you go around calling people who aren't transgendered "transexuals," please watch this video about this little girl, and realise that you're exploiting who she is just to insult a pop star you don't like.