I bet (=apuesto que) you didn't know that your teacher is an awesome(=excelente) football player. On May 23rd I'll be playing a football match against Ajax FC.
I'm not pulling your legs(=no os estoy tomando el pelo),this is 100% true.The match will be held (=tendrá lugar) in Amsterdam.The head of studies (=el jefe de estudios) knows that I'm an excellent player, so he has allowed me to (=me ha dado permiso) take a few days off (=tomarme unos días libre). I'll tell you about the match when I'm back (=cuando vuelva).I'll take pictures and post them in this blog. Needless to say (=sobra decir) that I expect you to show your best behaviour with whoever(=con quienquiera) comes to replace me.