dear june,try to talk to your parents,express your feelings,why you dont like that girl,why and how should an outsiders involve in one;s family for such a long period.is that bcos her house got burned down or is she too young to take care of herself?all of these couldnt make any senses .i would suggest solving the problems by communicate.try over and over,arguement only make things worse...
and for the penang trip,its hard to decide whether you go or stay.think you have to think them over yourselves.go?mayb you dont like the girl and ruin the whole party,or mayb you wont fell like enjoying the trip.stay?maybe you can earn some time calm your self down,also for your family,but who knows what will happens if you didnt go?

hope to hear any good news from you soon:))