battle of the bands.01/20/2011

there is a 'battle of the bands' competition at my school tomorrow. and i told my my mom about it, thinking that her and my dad might come. but she made me "invite" my sister, even though i DIDN'T and still DONT want her there. So i told her, and she said 'yes' and then 10 minutes later she tells me that she invited her fucking friend, WITHOUT EVEN ASKING ME!!!! Its my school, Im a student there, and Im not even sure how the BOBands is going to be like because its my first time to attend something like that :@ *im so mad* and then my mom had a pitty talk about my sister with me and then she started crying saying that she doesnt have a lot of friends - my sister(almost 20y.o.)-  and this and that... and YaDa YaDa Ya!!!!